Code P1135 Air Fuel Ratio Sensor

[Ron T.]

Does anyone know where the air fuel ratio sensor , bank 1 sensor 1 is located. Some of the posts I've read say it's on the intake manifold others say it's on the exhaust manifold. I'm getting a P1135 code and might have to replace the sensor. Knowing on which manifold and exactly where would be a great help. Thanks in advance!

[code58]

Does anyone know where the air fuel ratio sensor , bank 1 sensor 1 is located. Some of the posts I've read say it's on the intake manifold others say it's on the exhaust manifold. I'm getting a P1135 code and might have to replace the sensor. Knowing on which manifold and exactly where would be a great help. Thanks in advance.

Ron- the B1S1 is on the rear exhaust manifold. You have to get to it from underneath, meaning, unless you have a lift, you'll have to jack the car up. You will readily see it facing to the passengers side up high where it's not easy to get to. You're east coast so you may have a problem with rust. I would definitely use whatever rust buster you feel is most effective and the longest box wrench you can get your hands on. The hardest part is getting the plug unplugged, it takes 2 hands and you can only get 1 up there. I would suggest getting help- one person on top to hold the wiring loom taunt and the other on the bottom to pull on the plug. Otherwise you'll go nuts trying to do it alone. You may need to try to wedge something small in the locking tab on the plug so you are able to pull with 1 hand while someone holds from the top with 1 hand (neither of you can get 2 hands in there) I also suggest getting the sensor online where you can buy it for around $150. That's for original eq. Denso, the only thing I would recommend. I just noticed you have an ES rather than RX. Don't know how much different that will be, have to jack it up and see. That code is only the heater, so it's not urgent, won't hurt anything, may only run faintly rougher when cold.

[PK_3]

Code 58 is right and theirs know reason to get to excited but,as if you care, most cars are a peek efficiency and performance runing an air fuel ratio of 14:1. Your O2 sensor should keep it there.If it's bad, & that ratio bumps up to say 17:1, you run the risk of overheating your combustion chamber ...burning important things like pistons (really).

If it slips to say 10:1 it will run rich and economy will suffer, you'll foul things up. Doubtful you'll go to those extremes.

Thats got to be a real help. Don't know much as to its location but I can decribe one. It's about the size an shape of a of a spark plug. Has a plug with a wiring harness of 2 to 6 wires and Chilton has a mediocre manual that would probably cover this for $14 .

Regards, PK

[lenore]

here it is:

[CarPool]

here it is:

I found this info:

P1130 A/F Sensor Circuit Range/Performance Malfunction (Bank 1 Sensor 1)

P1135 A/F Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

Does the A/F sensor trigger 2 codes? The pictures for their locations are the same. I am confused! I ordered the sensor for P1130 and ready to install. Please someone clarifies if there are two locations for these two sensors or same. Mine is RX300 2K. Thanks

[Ron T.]

Hey everyone, thanks for the feedback. I looked at the sensor tonight. It looks like it could be changed from above on the ES. Probably with one hand on the wrench though. I'll ohm it out over the weekend and see if I can get to the root of it! I'll report back!

[Hadyourphil]

See my posts on the subject under "engine +vsc light" on the second page of the topics.

[code58]

Code 58 is right and theirs know reason to get to excited but,as if you care, most cars are a peek efficiency and performance runing an air fuel ratio of 14:1. Your O2 sensor should keep it there.If it's bad, & that ratio bumps up to say 17:1, you run the risk of overheating your combustion chamber ...burning important things like pistons (really).

If it slips to say 10:1 it will run rich and economy will suffer, you'll foul things up. Doubtful you'll go to those extremes.

Thats got to be a real help. Don't know much as to its location but I can decribe one. It's about the size an shape of a of a spark plug. Has a plug with a wiring harness of 2 to 6 wires and Chilton has a mediocre manual that would probably cover this for $14 .

Regards, PK

PK3- The good part about the P1135 DTC is that it is specific for the heater in the sensor. The sensor will function almost normally even with the heater bad. If in a cold climate it will affect it a little more, but after it's warmed up for a minute or so, the heater still can come into play, but there is no danger of the lack of heater throwing the F/A ratio off hardly at all. No danger of F/A ratio being in any area that could cause any damage. If you do a Google of "wide band fuel / air ratio sensors" you'll get a good idea of how much different they are than their predecessor, the narrow band sensor.

[code58]

here it is:

I found this info:

P1130 A/F Sensor Circuit Range/Performance Malfunction (Bank 1 Sensor 1)

P1135 A/F Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

Does the A/F sensor trigger 2 codes? The pictures for their locations are the same. I am confused! I ordered the sensor for P1130 and ready to install. Please someone clarifies if there are two locations for these two sensors or same. Mine is RX300 2K. Thanks

It CAN trigger both of those codes, but if I got both of the codes, I would reset (cancel) the codes out and see what comes up. It is rather imaterial because if either of them are legitimate it still requires replacement. If the heater is bad (one of the most common failures in A/F ratio sensors), the light will be back on shortly. There ARE 2 of the same sensor (A/F ratio), 1 on the front manifold and 1 on the rear manifold. That's the reason for B1S1 and B2S1. B1S1 is on the rear manifold by the firewall and B2S1 is directly below your nose when you open the hood and lean over the engine. Bank 1 and Bank 2. I hope you got original equipment Denso sensor. Some people luck out with the aftermarket and some people still have troubles they can't figure out after they've replaced with aftermarket. I personally wouldn't use anything but OEM Denso.

[blueridge]

I got both codes once or twice during this problem where I reset the CEL about 20 times in 5 days. However, the 1135 code was the one that kept coming back on. P1130 only came on twice with the P1135, replaced the sensor with OEM and the light has stayed off since.

[Ron T.]

I inspected the sensor the other day and moved the wires a bit, preparing myself for the task ahead. Strangely, after driving about 100 miles, the engine light hasn't come on again. I can only conclude that there is a loose or broken wire to the sensor.

Any ideas or suggestions?

[code58]

I inspected the sensor the other day and moved the wires a bit, preparing myself for the task ahead. Strangely, after driving about 100 miles, the engine light hasn't come on again. I can only conclude that there is a loose or broken wire to the sensor.

Any ideas or suggestions?

It's a bummer Ron, that it is the rear sensor, that's so much harder to get to than the front one. My suggestion would be to go to Radio Shack or anywhere you can get electronic control cleaner and lube (small spray can). Pull the plug apart and spray both sides with the spray. If you can, with help, pull the plug apart and reset a few times. You can inspect for broken wires while you have it apart the 1st time, but I'm betting it could just be a little dirty rather than a broken wire. If so, that should take care of it. For future reference, ANY TIME you have problems with a problem that involves a plug, (meaning the signal goes through a plug, almost all do), the 1st thing you should try is what I just suggested. What are carried through the wiring looms of modern cars so often are signals that are very low amperage (and sometimes even low voltage) that are interrupted by a dirty connection that doesn't even look dirty. If the 1st thing you do is what I suggested, you may very well save chasing your tail for days, and keep the blood pressure down as well. Remember... 1st, not last.

As a P.S.- the code you got was P1135 which is the heater, a common failure on those sensors because they run VERY hot when they are on, resulting in broken heating element.

[Ron T.]

Thanks so much! Sounds like good advice. The engine light hasn't gone on since I fooled with the wires. So it looks to me like you got it right! I'll clean the connector and report back!

Thanks again!

[NJerseyDan]

Hey guys. I got a P1135 as well. I've seen mentioned in a few other threads that you can easily test the heating element. I've pulled it out, but dont know which wires to test. The connector has two black, one white, and one blue wire. Also, is there a way to test the sensor itself?

2001 RX

[code58]

Hey guys. I got a P1135 as well. I've seen mentioned in a few other threads that you can easily test the heating element. I've pulled it out, but dont know which wires to test. The connector has two black, one white, and one blue wire. Also, is there a way to test the sensor itself?

2001 RX

Dan- the 2 wires you want are the black ones. You can test continuity either way on wires. The resistance should be .8-1.4 Ohms at 68 degrees, but I'm betting the heater element is broken, in which case continuity is all you'll need to know. Since the P1135 is specific to the heater, nothing else in the sensor, you won't need to test the other functions. The factory doesn't give a way to test them anyway.

[NJerseyDan]

Thanks Code. The two black wires are showing NO continuity. Off to the store. I'm probably gonna pick up http://www.speedycarparts.com/catalog/?&Ntt=234-9009 ,though I would rather buy it in a store and slap it in today. Do you have any input if I were to buy from a local car parts store?

[code58]

Thanks Code. The two black wires are showing NO continuity. Off to the store. I'm probably gonna pick up http://www.speedycarparts.com/catalog/?&Ntt=234-9009 ,though I would rather buy it in a store and slap it in today. Do you have any input if I were to buy from a local car parts store?

NJDan-My only input would be to use ONLY Denso. The price from SCP is very good. The same thing as the original Toy/Lex sensor but a lot cheaper with the Denso # on it. I doubt that you will be able to get near that price from a local store. NO aftermarket sensors!

[NJerseyDan]

My sensor came in today, and the that got rid of the check engine light and VSC. I bought it from SpeedyCarParts on Tuesday, so it came pretty quick. If anyone is looking for the sensor immediately you can buy it from a Toyota dealership for 212$ after tax. It's the same part you'll buy at a Lexus Dealer- and they will probably charge you more.

My RX is almost at 100K. I'm wondering if the heating element on the other sensor is gonna fail soon. Has anyone had the happen?

[code58]

My RX is almost at 100K. I'm wondering if the heating element on the other sensor is gonna fail soon. Has anyone had the happen?

NJD-I wouldn't personally worry about it. The rear one is the one that goes first about 90% of the time or more because it gets so much more heat on the back side of the engine. Even if the front one does go, it doesn't really hurt much of anything, just slightly rougher running for a minute or so until the exhaust warms the sensor up. You can still replace it when you have time, with no worries. If you feel you'd rather do it on your schedule, go ahead and do it. I figure most of the time, if something like a sensor is still working fine, what if you trade the car 6 mo. from now or it is stolen or totaled- you didn't lose the new sensor that you didn't really have to replace. Your call - your money.

[NJerseyDan]

Nope. If it's the rear one that cursed, then I'll leave the front one alone!

[gonowhere]

" You may need to try to wedge something small in the locking tab on the plug so you are able to pull with 1 hand while someone holds from the top with 1 hand (neither of you can get 2 hands in there) I also suggest getting the sensor online where you can buy it for around $150. That's for original eq. Denso, the only thing I would recommend. I just noticed you have an ES rather than RX. Don't know how much different that will be, have to jack it up and see. That code is only the heater, so it's not urgent, won't hurt anything, may only run faintly rougher when cold."

W here should the wedge go into the locking tab? Outside the tab I suppose? It is driving me nuts to disconnect the harness plug. Thanks.

[code58]

GNW- I wish I had a link for a VERY good post (with pictures) of the plug and how too get it released. Don't remember if it was on here or Club Lexus, but I'm sure that you can find it with a search. It can be a bugger, but I can say the guy who posted what I'm talking about was able to figure out a way to do it a whole lot easier than usual. If you have help (someone on top and you on the bottom) it works a whole lot easier. If they can reach in with the proper hook tool and release the locking tab and hold the loom taunt while you pull it sideways from the bottom, it should come right out. With only one person, it's hard because you need to get both hands up there at once and that's not possible. Good Luck!

[code58]

Deleted: Double post

[gonowhere]

Sucess! I wedged in a screw driver from the top to push the tab inward and left it there. Then I went under and unpluged it. Bought a curved 7/8" wrench to loose the senser. Replaced with a junkyard senser. Disconnected the battery. When I stated the car, the lights are gone. and thanks a lot for the info.

[code58]

Glad to hear of success! I sure hope the used sensor was cheap, I probably wouldn't trust a used sensor very far, unless I was getting rid of the car, or it was awfully cheap.