code58

P-L, You can probably find a bunch of info on this subject because it has been discussed a lot on the Lexus forums. Get the code read at Autozone or 1 of the places that read for free and post here so we can help you further. Make sure if it is code for 1 of the front sensors that you get Air/Fuel Ratio sensors and not oxy. sensors! It's real easy if it's the FRONT 1- not as easy if it's the rear 1. (Harder to get to). Post back and we'll help you out- quite a few guys here that have had experience with it.

Now I've gotcha- appreciate that clarification Lenore. I don't like using after market parts unless I have to, but I was in Pep-Boys for some other parts and thought I'd take a chance on the belt (Dayco) because the original was Dayco/Toyota. That's not the first time I've been bitten by after market belts- you'd think I'd learn! To top it off, the belt was $22. You'd think I'd learn! :( Y/T- Roger

Now I've gotcha- appreciate that clarification Lenore. I don't like using after market parts unless I have to, but I was in Pep-Boys for some other parts and thought I'd take a chance on the belt (Dayco) because the original was Dayco/Toyota. That's not the first time I've been bitten by after market belts- you'd think I'd learn! :( Y/T- Roger :)

Code58, I am with you re the squealing which is why I asked the question. Here is my best guess: the new belt was slipping but not squealing because it had not yet glazed. I'll let you know if anything changes. When you consider the low contact angle of the belt on the A/C compressor pulley, I would think you need pretty good belt tension to drive it. I have wanted a belt tension gage for over 30 years now and I think I am going to buy one. I'm getting too old to be guessing if I have enough belt tension!! I'm not a mechanic by trade, but worked on cars for about 40 years. I think it's pretty hard to over-tighten a new belt. They usually stretch a small amount after a few miles. You'd have to use a pry bar or something and really reef on it, but I suppose it's possible. I too have always been careful when tightening my belts. It's kinda like doing valve lash adjustments, it's a acquired "feel". You learn something new every day eh, artbuc? I don't see what year RX you have artbuc but I have had some recent experience with belts. I recently replaced the a/c-alt. belt on my DIL's 99RX300. I used a Dayco Premium belt (the original belt was a Dayco/Toyota) This is the belt with the notches in the grooved side. After a couple of days my DIL informed me that it was squawling for about 1/2-1 second at startup and then would quite. I knew I had adjusted it tight enough (I've been adjusting belts for over 50 yrs.), and figured at 120k that the compressor was finally going. I told her not to use the a/c until I could fix it. Before I got a chance to get the car she told me it had done it a couple of times with no a/c on. I checked the belt and it was tight enough and so I spent the next 1 1/2 days tearing everything apart to check the water pump, both idler pully's, alt. bearing, comp. bearing, comp., etc. (checked it all 1st. with mech. stethescope), and found nothing. I was at my wits end (it had never made the noise for me but I had heard the noise once when my son started the car). It squealed like a banshee. The thought finally came to me to compare the new belt to the old one. I took a mic and miced all the dimensions on both belts and there wasn't a lot of difference but there appeared to be a small difference in the angle of the taper of the walls of the grooves on the new belt. I put the old belt back on, adjusted it to the same tension an viola- no more squawling. I feel the squawling was until it spun the alt. up some, as the a/c pulley would offer no resistance without the a/c on. I probably could tighten it tight enough to stop the squawl but I feel then it would be overtightened to compensate for the improper angle of cut on the grooves. I will return it and get a Mitsuboshi orig. eq. belt. I thought because the orig. belt was Dayco that it would work well but as sometimes is the case, after market even by an orig. eq. man. is not built to orig. eq. standards. Darn belt wasn't cheap either! :( Roger artbuc- you mentioned the "low contact angle" on the comp. belt- my DIL's RX has about a 90 degree turn around the comp. pulley, maybe I didn't understand what you meant but that doesn't seem like "low contact" to me. It get's a pretty healthy bite on that pulley.

Code58, I am with you re the squealing which is why I asked the question. Here is my best guess: the new belt was slipping but not squealing because it had not yet glazed. I'll let you know if anything changes. When you consider the low contact angle of the belt on the A/C compressor pulley, I would think you need pretty good belt tension to drive it. I have wanted a belt tension gage for over 30 years now and I think I am going to buy one. I'm getting too old to be guessing if I have enough belt tension!! I'm not a mechanic by trade, but worked on cars for about 40 years. I think it's pretty hard to over-tighten a new belt. They usually stretch a small amount after a few miles. You'd have to use a pry bar or something and really reef on it, but I suppose it's possible. I too have always been careful when tightening my belts. It's kinda like doing valve lash adjustments, it's a acquired "feel". You learn something new every day eh, artbuc? I don't see what year RX you have artbuc but I have had some recent experience with belts. I recently replaced the a/c-alt. belt on my DIL's 99RX300. I used a Dayco Premium belt (the original belt was a Dayco/Toyota) This is the belt with the notches in the grooved side. After a couple of days my DIL informed me that it was squawling for about 1/2-1 second at startup and then would quite. I knew I had adjusted it tight enough (I've been adjusting belts for over 50 yrs.), and figured at 120k that the compressor was finally going. I told her not to use the a/c until I could fix it. Before I got a chance to get the car she told me it had done it a couple of times with no a/c on. I checked the belt and it was tight enough and so I spent the next 1 1/2 days tearing everything apart to check the water pump, both idler pully's, alt. bearing, comp. bearing, comp., etc. (checked it all 1st. with mech. stethescope), and found nothing. I was at my wits end (it had never made the noise for me but I had heard the noise once when my son started the car). It squealed like a banshee. The thought finally came to me to compare the new belt to the old one. I took a mic and miced all the dimensions on both belts and there wasn't a lot of difference but there appeared to be a small difference in the angle of the taper of the walls of the grooves on the new belt. I put the old belt back on, adjusted it to the same tension an viola- no more squawling. I feel the squawling was until it spun the alt. up some, as the a/c pulley would offer no resistance without the a/c on. I probably could tighten it tight enough to stop the squawl but I feel then it would be overtightened to compensate for the improper angle of cut on the grooves. I will return it and get a Mitsuboshi orig. eq. belt. I thought because the orig. belt was Dayco that it would work well but as sometimes is the case, after market even by an orig. eq. man. is not built to orig. eq. standards. Darn belt wasn't cheap either! :( Roger

artbuc- If the alt. belt (also a'c) is loose enough that you aren't getting any a/c, you are bound to have squealing. I don't think there is much chance of having NO a'c and tightening the belt that small an amount and regaining your a'c. I agree with Lenore in the amount that the belt should be tightened but I would 1st. visually check to see that the compressor clutch is engaging when the a'c is on. You may have a fuse blown or a small hole in the condenser from dabrie that let the R134 out. Tap the low side valve with a small screwdriver to see if the system still has a charge. Could the system be a little low and the low pressure switch shut the compressor clutch down? I would personally be a little surprised if you have NO a'c and it is just a minor belt adjustment. Let is know what you find out. <_<

thanks for your responses. that is what i am doing now (well the dealer is having me drive around checking the oil to take it back to have them measure any needed adding of oil. i am wondering if they have added an heavier weight oil for the consumption test and if so, what harm would it do to the working parts of the engine to run a heavier weight oil permantly if that takes care of it? Did you buy this from a Lexus dealer? Clearly there is a problem if they did fill with oil and you have used 3.5 qts. in 2k mi. It's a '02- I hope you got some kind of a warranty if you bought it from a dealer, new or used. A heavier oil- if the dealer is dishonest enough to use it for consumption testing, is not at all likely to stop that kind of consumption. You need to compression test and leak down test- this is not normal for a '02- unless it has been severely overheated and the rings damaged. Even then- that is an all aluminum engine and would likely have warped block and/ or heads if that severely overheated. you say the spark plugs were black- were they wet with oil or only black? Only black sounds like excess fuel- not oil. Good Luck- that is clearly not normal and not likely cured with heavier oil.

Thanks Indiana for re-reminding the folks that are just facing this VERY COSTLY repair for the 1st. time. There has been a lot written on it in the past- search will show. Also on Club Lexus. I did it on all 4 doors on my DIL's RX at actually $0. with free donated locks. You have to leave all the old lock actuators in place because they have all the strip sensors inside to operate all the other stuff that they interface with. Also, you don't have to drill any holes, there are already existing holes in the mechanism that aren't used. The drivers door works fine with the "piggy-back" lock- just like the original did. I could not see putting out $1300. for locks when this works just like the original and retains all the functions of the original assemblies. (sensors and all) They have worked flawlessly for almost 2 yrs. now. I just used 90 degree taps on the wires to piggy-back the wires onto the existing wires without cutting them. That's no problem here in corrosion free So. Cal.- wet areas probably should solder and water seal the connections.- Roger P.S.- Don't be intimidated by the write-up on taking the door panels off- It's actually not bad once you've done one, by the second or third you could do it with your eyes closed.

Hi Lenore- I like your sense of humor :D - and also agree with you on rebuilding your own unless you have a known bad field or stator. The rebuilts in my experience are too much of a crapshoot. My brother got 3 bad ones (right out of the box!) for his son's car before he got a good one. I once bought one for my son's Camaro (years ago) and decided to pull the bolts and look inside before I installed it, because of past experience. They had twisted one of the field wires right off (with an impact), and stuck it in the box and shipped it. I have many other stories but you get the idea why I don't care for rebuilts.- Roger

It isn't that hard to pull the front cover off. I believe there are only 10mm (head) bolts - and not an awful lot of them at that. Course I spent 30+ yrs. doing that work. lol There may be an easier way though- there is a type of pop rivet that " kneels". It is split into 1/3rds. It provides plenty of holding power and is used by many auto manufacturers to do exactly that- hold license brackets on rubber bumper covers. It is not a standard pop rivet. When it is set it puts 3 legs out in 3 directions as if a 3 legged praying mantis folded it's knees completely. Quite effective and no removing the bumper cover. Hope that helps.- Roger Certainly some body shops should stock them and not charge you much to install the bracket. They come in plastic and metal and I would use the metal if you can find someone who has them.

Funky- I have tried the "universal" sensor that you are showing and no they are not "click out and click in"- and also they didn't work. They were Denso but even though they assured me they were the correct ones, I believe the reason they didn't work is because they were probably oxy.sensors rather than air/fuel ratio sensors which is probably what you are thinking of. The sensors on front and rear exhaust manifolds are a/f ratio sensors and the (one) sensor behind the cat.con. is an oxy. sens. Read my answer to the post a couple from this for more info. Y/T Roger

FS- the part# you will need is Denso (orig.eq.) 89467-48011 IF you need a new one. You can buy it from a particular Lexus dealer online for $150. or on e-bay in a Denso aftermarket but same part as original Toy.-Lex. for about $125. That part # is 234-9009. ONLY use Denso in one of the 2 above! Roger The rear one is Bank1, Sensor1- as you have discovered.

RXE- Did they give you the snake oil with that? I'm not sure where it would go, but they charged you for it, you should have gotten it. I would have expected that from a shop in the alley, but not from Lexus. That's a new low in flimflamery. You know where not to go back to. :o

You are exaclty right Mikey: the battery I got is #3. Apparently the size has changed. Good point on the WD40. Will give it a go. Thanks!! Hi Fransisco- I installed a Costco battery in my DIL's 99RX300 (#3) and it fit perfect. I might suggest on thing on the rear bolt though, if it does not come off fairly easy with the use of penetrating oil, you may have to remove the air cleaner box so that you have axcess to the rear bolt to hold it with pliers or vice grips. A better suggestion would be to remove both cables first and after you have removed the front bolt, turn the bracket 90 degrees and you should be able to slip the old battery out and the new in without even dealing with the rear bolt. I have done this numerous times when I was in a hurry just to save time even on one where the bolt would come out. It generally works fine. Hope that helps. Roger Matter of fact when I stop to think of it, I think when you remove the front bolt the hold down should just pivot up and come out of the lower hole without ever loosening the rear nut.

Hi again Lenore- Yes, that is the heater resistance- .8-1.4 ohms on the 2 black wires (heater wires), although mine tested 1.5 ohms on the good a/f sens. that I took out. Although it does have 100k+ on it. LOL Y/T- Roger :)

Hi Lenore- I believe the A/F sens. ratio resistance should be .8-1.4 ohms. The oxy.sens.ratio, at least in my factory Lexus manual is showing 11-16 ohms. I just coincidently checked the ohms on the good front sens.(B2 S1) that I had removed when I replaced them on my DIL's RX, this afternoon, and it read 1.5 ohms. I have noticed 1 thing about Lexus paramaters- sometimes when you check a part and it is completely outside of the paramaters, it may still work perfectly fine . I found that more than once when working on her car. The IAC completely failed in typical Lexus fashion- I removed it and cleaned it and it worked great (idled perfectly) but I test everything before I cleaned it and the electrical servo tested bad (59 ohms in one direction and 2 in the other). I chose to replace it even though it functioned perfectly because of the crisis situation that had the car in Seattle for several months. Don't know what to make of those type of situations (it wasn't the only one). Thanks for your posts Lenore. Y/t- Roger

Hi Lenore- I see you on F-150 online as I am also a F-150 owner. The heaters aren't wired in series as that is the reason for the P1135 and the P1155 tc's. The 1135 being rear sens. and the 1155 being front sens. When my DIL's RX threw the P1135 code the car was in Seattle for an extended time and I had to figure it out without the car here. When I ultimately figured out what was going on I told her to go ahead and drive it, it wouldn't hurt it , and I went ahead and fixed it when the car was back down here. I did ultimately replace both sensors because the car had to go back to Seattle again for an extended time and I didn't want her to have trouble so far from home. But the replacement of the rear sensor did deal with the CE light. When I dissected the defective sensor , sure enough, the heater wire was broken. I don't necessarily think that is his problem because I still say it is UNLIKELY they both broke at the same time. As you said an ohm check of the heater contacts on the plug will tell the story. Trust he lets us know what the problem was when he finds it.

it would be wise to clean all surfaces that has any oil leak residue. Make sure the leak is complete clean. Recheck and confirm that the leak is not oil residue from oil filter removal and or rear main engine oil seal. It is very rare to have the number one oil pan to leak on those model. If it did not leak for soo many miles it is unlikely to have the number one oil pan leak because of how they seal those in the factory. Thanks for letting me know that the upper pan is designated as number one oil pan. I am absoulutely sure that the leakage is from this pan. We had it up on a lift and with the engine running. Oil was squorting out in front of my eyes. I am disappointed by Lexus that they choose to seal it with a silcone. I will call Lexus tomorrow and will hear what they have to say. As has been stated, that is the way they are sealed at the factory and is a much better way than when gaskets were used. I suspision the mechanic was a little careless when installing the pan and disturbed the silicone or didn't let it cure long enough before he added the oil. When done properly it is an excellent seal. It DOES take time for it to set. Good Luck in getting it resolved. :)

Hi Gtar- Your 1st. post is hard to understand. Did you actually unhook the battery? For how long? I would try unhooking it again for maybe 20-30 min. Then have it read again if the ce light comes on again. Those two codes refer to the heater being bad in both the front a/f ratio sensors. (R&L- in the exhaust just beyond -after the exhaust manifolds) Not real likely they both went bad at once. There is a way to check them with a DVM, as they are pretty expensive you don't want to replace them if you don't have to. Let us know how it goes.- Roger

Let us know how it goes. It would be nice to hear some good news about plug changing in the RX. I already had the T/B off because I was replacing the IAC but was able to reach around the back from both sides- a stretch but I made it. I pulled 1 of the front plugs out today just to see how it looked (replaced them 20k ago) and was amazed that it looked virtually new! I have read that iridium is the hardest metal known to man- I believe it! :o

Greetings- I changed my DIL's at 97k and was suprised at how good a shape they were in. (99RX300) A true testament to the quality of iridium. I would say if your mileage hasn't dropped off and it runs good, go for it. I'm sure I'll be flamed for that advice. I did not remove the upper intake manifold but I did remove the throttle body. Just didn't want to go hunting for gaskets. It wasn't easy but it was doable. Don't know if the '04 is any different in that respect (engine compartment) or not but I dought it. Good Luck

Absent knowing, having a LONG service history with the non-marque shop involved, I would NEVER take a modern high technology vehicle to a third party shop. In short, you've just been screwed. Now take it to Bellevue Lexus and get screwed yet again. But at least you'll get the car fixed properly. Wow. This is one of the worst hosings I've heard about in a long time. At 86k miles, I seriously doubt you needed a new tensioner, thermostat, carbon clean service, exhaust manifold or new plugs. At 83k, the original spark plugs on my RX look brand new. Did they show you the old tensioner and explain what was wrong with it? Why did they replace the exhaust manifold? Was the water pump bearing showing signs of failure or did they replace it just to be safe? Did they get your approval in advance? Regarding the new work, P0125 & P1155 together indicate you need a new Bank 2 Sensor 1 (A/F) which will cost about $150 for a quality aftermarket Denso. It should take less than 1/2 hour to install it. Yes, IMHO, their work almost certainly caused the A/F Sensor failure although I had an A/F Sensor fail on my Avalon (also has the 1MZFE engine) at less than 85k miles. Just too much of a coincidence that yours failed right after they assaulted your RX. P0125 & P1155 codes together indicate the heater circuit in you Bank 2 Sensor 1 is shot. Did they replace the Bank 2 exhaust manifold? Could be something as simple as they forgot to reconnect the B2S1 and they want to charge you $500 to do a 5 second job. You can confirm the B2S1 heater circuit is fried with a 15 second ohmeter check. A shop claiming specialty in SUV's is like finding a doctor who specializes in parts above the waist. Pretty meaningless claim. I don't know what you do for a living "artbuc" but that is a very perceptive post. I am always glad to see TRULY knowledgeable help like this extended to those that need the help. Congratulations! The P1155 (front a/f ratio sensor) is a 15 min. job and can be checked with a Dvm as artbuc said. My only suggestion would be that you only use ORIGINAL EQ. Denso which you can buy from the right source for that amount. Denso does make aftermarket sensors and the ones I tried did not work. I feel there is a chance that if they changed the front manifold and either dropped the sensor or were a little rough with it they could have broken the heater element. They run at a very high temp when they are on and therefore could become brittle over time. The W/P, tens.,spark plugs and possibly other parts are parts that Lexus would recommend you change at those miles are not parts that necessarily need to be changed because of end of life issues. I have dealt with all of these issues on my DIL's RX300 and I can say that at 97k though I changed them (some of them) for some very specific reasons, most were not worn out by any means. (I have spent my life in automotive work-just as a background) All parts were original and the timing belt showed NO signs of wear or cracking at that age. The plugs were in remarkable shape for 97k. The w/p as well as tens. pully were smooth as new and NO sign of leaking. If your wallet is fat and you chose to by all means change them, but not because they are necessarily at the end of their life. 2 coils dead? That thing must have hardly run. I'm not saying these people were dishonest, but at the cost of auto repairs today, it upsets me that there are not more TRULY HONEST shops, treating people like they were spending THIER money rather than YOURS!. Again, thanks "artbuc" for the knowledgeable and competent councel you gave Harry, Y/T- Roger

Hi Harry- To begin with I believe you will find that P1155 is Bank 2 Sensor 1, which would be the front 1 on the exhaust manifold straight down when you open the hood. P1135 would be for Bank 1 Sensor 1- in the rear. The 1 Lexus specific code chart I checked has an error there. If they are quoting you $500.00 for just replacing that sensor that is pricey to say the least. I replaced both of them on my DIL's 99RX300 and was able to get them from a Toyota dealer for $162. ea. plus tax and could have gotten them from a Lexus dealer online for $150. ea. plus shipping and tax (Ca.) if I had had the time to wait. They only list from Toyota for a little over $200. ea. Secondly, the P0125 lists 1. Insufficient warm up time 2. Leaking or stick open thermostat 3. Faulty coolant temperature sensor 4. Low engine coolant level There are other things that can cause the P0125 and I reluctantly have to agree with the earlier poster that often the dealer (stealer) has a better handle on pinpointing the problems than an independent. You just have to bend over and grab your ankles, but I'm not absolutely sure you haven't had to do that already with the independent. Best of luck and let us know how things turn out. Y/T- Roger

Should be no problem-KYB is good stuff.- Roger