ULTM8Z

yep, bad battery.   Hallelujia!   thought I was going crazy!

I'm going to take the battery back to Pep Boys and have them test it...

ok, now I'm realy scratching my head...  

after 2 minutes it drops to 25 mA.   That seems within the realm of being nominal for this kind of car.

SO maybe it's just the battery is not holding a charge... which is odd since I think it's only 2 years old (a Bosch).

Interesting... watching the ammeter...

It starts out at 600 mA, then after 10 seconds it drops to 250 mA.    Consistentyly does this... I hook up the ammeter, starts at 600 mA.... then after 10 seconds, drops to 250 mA.

understood on the fuseable links.  But those are typically designed to protect circuits with high transient inrush currents.

There's something that's pulling a significant enough current to brightly light the bulb and even generate sparks when I go to connect the cable back up.

Put an ammeter on it and it's pulling 600 mA.   That's a lot of current drain...

Just tried a different battery to rule that out... nothing.

IS there some part other part of the electrical system that's not going through the fuses?   I would think any kind of a small short on the unfused part of the +12V main wiring would cascade into a full blown short pretty quickly.

2005 RX330.

I disconnected the negative terminal and put a light bulb in between the cable and terminal.  It's shining very bright, indicting significant current draw.

Went around to every fuse under the dash and engine compartment.  Also disconnected the alternator main cable as well as wire harness.  The light stayed on continuously and never even dimmed.

Is there something/somewhere else I should be checking? 

By the way, the Lexus part number for the '99-02 A/F sensors for the RX300 is 89467-48011.

So the ones in the exhaust manifold are A/F ratio sensors, not O2 sensors.

I noticed it when the service engine soon light came on and I scanned the car. I have a 1971 Camaro that I swapped in a 1992-era EFI system, so all of my EFI knowldge comes from that effort. It uses narrow band O2 sensors which bounce back and forth, hovering around a centering voltage (typically around 500mV). This Lexus system seems to operate differently based on what you all are describing?

These A/F ratio sensors you guys are talking about appear to be what I know of as wide band sensors?

So I'm going to break down and buy three new O2 sensors. The car has one at each exhaust manifold and one downstream of the cats.

My scanner is showing all three sensors basically stuck at one voltage (right around 700 mV) rather than bouncing back and forth like I'm used to seeing on my other cars. First of all, the car only has 45k miles on it. Would the factory O2 sensors fail that quickly?

Nonetheless, as I'm browsing online I'm seeing sensors by Bosch and Denso ranging from $50 universal types to over $200 for what seem like more vehicle specific. What's the deal? Aren't these all just plain ol' narrow band heated sensors? Why the wide range in pricing? What exactly is needed? CAr is a 2005 RX330.

There's an easier way to get to the oil filter. I just took the heat shield off the exhaust manifold and then I could access the filter from the top of the car- three 10mm bolts and it was off. If you don't take the shield off, the filter won't fit between the shield and the cooling fan to get it out.

Also put some paper towels under the filter to catch any dripping oil. So much easier than removing that access panel under the car.

Trying to change the oil for the first time on a 2005 RX330 (I always do my own oil changes, but this is the first one on this car since the time we bought it used). I found the drain plug for the oil pan, but I can't find the oil filter. Any help would be appreciated. Is it on the top or bottom of the engine.

Nevermind... I just found the oil change DIY section here on this site.

Trying to change the oil for the first time on a 2005 RX330 (I always do my own oil changes, but this is the first one on this car since the time we bought it used). I found the drain plug for the oil pan, but I can't find the oil filter. Any help would be appreciated. Is it on the top or bottom of the engine.

Denso had a rash of AF sensors that were not very reliable. They were crap our short of 50k miles. These were seen alot in the 2002/2003 V6 used in the ES, RX, Avalon, Camry and other Toyo vehicles. Many people complained but Toyota did not do much except replace them under warranty. If you were out of warranty, then you paid. Supposedly they sensors have been improved and are more reliable.

That being said, I had one AF sensor go at 39k miles and one go at 58k miles on my 02 ES. My 06 GS has yet to throw a sensor and I am at 52k miles.

I sold my 02 ES with 108k miles on it and the O2 sensors in the it were still the original.

steviej

Both sensors are saying the same thing... about 720 mV. Either they both crapped out and are stuck at the same value, or they're reading correctly a rich condition.

The other curious thing was the 16% throttle reading at idle even when my foot is off the accelerator. Not sure how Lexus PCM's work, but on my Camaro that would certainly cause an fuel mixture enrichment at idle speeds- which would certainly peg the O2 sensors into the high mV output.

I guess I'll have to see if I can find someone else's Lexus I can scan and compare the data...

Are we talking the Check engine light or the Maint required light.

If it is the yellow icon that looks like an engine block then that is the CEL and you should be able to pick out codes in memory.

If it is the maint. reminder light then check to see when the last time the oil was changed. The newer Lexus models have a reminder light that flashes at 4500 miles when you start the engine and stays on steady at 5000 miles since the last oil change.

This is covered in your manaual. If you vehicle didn't come with a manual, I can tell you how to get one free.

Lastly, search on maintenance light reset or something like that. There are plenty of threads telling you how to turn it off. . . very simple.

steviej

Thanks for the reply. Yes, the maintainance required light. I know how to turn it off, just want to make sure I'm not ignoring something important.

The data I retrieved and posted about above is still of concern since to me it appears out of the ordinary. How often to O2 sensors last on Lexus vehicles? I'd be hard pressed to think that both O2 sensors crapped out, so I'm wondering if something could be causing a rich condition.

Greetings, I'm new to the forum, but not new to cars. We have a 2005 Lexus RX330 that we bought used with ~39,000 miles earlier this year. Great car. However the maintainance required light came on a few days ago.

Being a gear head in my spare time, I know my way around cars (my hobby is a 1971 Camaro that I swapped in late model EFI). I have an OBD-II scanner, so I scanned the Lexus and no trouble codes were set. I did notice some curious things on the real time data and wanted to bounce it off you guys to see if there's an issue here.

1.) TPS sensor is reading 16% at idle with throttle closed. In all the other cars I've scanned, it typically reads 0%. I did step on the accelerator and the TPS % does increase smoothly.

2.) The scanner is able to read two O2 sensors. Though I'm not sure if the vehicle only has two. In any event, both O2 sensors were very sluggish in their responses, basically hovering around 720 mV... changing by about 10 mV every second or so. Again, on my Camaro, the O2 sensor bounces around quickly around a centering voltage of ~450 mV. If this were the Camaro, I'd conclude that something is pegging the exhaust into the rich zone or the O2 sensors are bad. Not sure if this is normal for Lexus

3.) Long term fuel trim is ~10%. That seems like a lot for a factory tuned car. I'm able to tune my Camaro to within 5% without a dyno or anything. The fact that this Lexus is off by 10% (combined with the O2 sensor data) leads me to believe there's some issue with the fueling???

Thanks in advance for your help