Check Engine Light + Trac Off

[McGuyver]

I am a newbie, but I have to know if anyone else has had problems with the front and rear bank AFI ( air fuel indicators) or what was once known as oxygen sensors.

I purchased my '99 ES300 (used - 55K miles) 3 years ago from a Toyota Dealer and within two months, the CEL and Trac Off lights came on. [ BTW: The Trac Off light will come on anytime the CEL is on] When the codes were checked, it was the rear bank AFI and $675 (Yeow!) later that sensor was replaced.

Almost 60 days later the front bank AFI sensor failed and I replaced it myself for $497 (sensor cost + sales tax) Yeow!

Since that time the Peddle position sensor has also failed and been replaced.

Last week the CEL & Trac Off light came on again. The codes indicate the rear AFI sensor has failed again. That sensor failed in less than three years and 36K miles

Is this normal? The Service manager at the Local Lexus dealership says it "happens occasionally".

I find it hard to believe that an oxygen sensor should fail that quickly - it's just a heated wire for crying out loud. My volvo had over 250K miles when my older son crashed it, and the sensor in it was never changed. All 5 of my trucks have never had a bad exhaust sensor.

Has anyone else had this problem? Could there be something else that is causing these sensor to fail?

I need help with this. This is my wife's car and I feel like contacting the regional manager for Lexus and ask him, if I could find out who that fellow is.

Any help will be greatly appreciated.

[SKperformance]

Where did you get you replacment parts?For the prices mentioned it would sounds like what the dealer charges.

I would search

as your MAF could use cleaning

as well as this is a constant question for a rear failing o2 sensor

[McGuyver]

Where did you get you replacment parts?For the prices mentioned it would sounds like what the dealer charges.

I would search

as your MAF could use cleaning

as well as this is a constant question for a rear failing o2 sensor

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I got the sensors from the dealership, because at the time I could not find a supplier for the 4-wire sensor. I cleaned the MAF when I changed the front bank sensor.

The car has a history of CEL events. Every so often the CEL would lite off and then in a day or so or even sometimes just a few hours would self extinquish. This has happened so often that my wife has started to ignore the indicator all together. It wasn't until I drove the car while she was on a business trip that I noticed the CEL and had the codes checked. I asked her how long it had been on and she just said "a few days...maybe longer". It is really no telling how long the car has operated in the default mode.

[SKperformance]

CHeck for manifolds being cracked.

This is a consitant problem and most people are selfish and never come back to help anyone else with a resolution.

So far it seems the MAF can throw the rear o2 code by running it lean.

I don;t know how i just read it.

I also do not own a 97 ES manual to know what the resistance and test procedure is for your year which could fortify if the maf and/or o2 is bad.

Second is there seem to be some defective o2 sensors that were bought from toyota and resold as bosch .This is a problem that a RX owner is working through right now.

They also had a cracked exhaust manifold also which was causing a problem.

[McGuyver]

Thanks for the info.

The codes indicated that the Bank 1 Sensor 1 was malfunctioning [P1133 & P1135] and I was told by the dealership that this is the unit at the firewall. True?

[For some reason, I cannot trust a dealership service manager - maybe it's because the my new '84 Volvo GL caught fire and burned to the ground in a dealership parking lot with its first oil change. BTW: I did get a brand new car, baby seat, a complete set of Craftsman tools which I had just bought that morning, and an apology. I never went back there - but that was the same Volvo my Son crashed].

My wife's ES was made in Oct 98, so that puts in the midst of the sensor problems of that time. Evidently, the complaints got bad enough that Lexus issued a TSB (#EG004-99). The bulletin only states if routine checks do not solve the ECU code to replace the original AFI [#89467- 41020] with the supplied replacement [# 89467- 41021]. It would seem that there IS an issue with the Bank 1 sensor on this particular model, if a TSB was issued for the cars made from 8/1998 to 7/1999 ( Cal - 8/1997).

FWIW I believe there is something amiss with the ECU & AFI interface.

At this point it doesn't matter, my wife loves her car and I have to keep it going for her, so I will snatch that bad sensor out every three years if need be.

There are a few online parts suppliers that offer a Denso replacement unit [C5015-137284] for around $200, but I have never dealt with any of them.

Can anyone tell me if they have dealt with Auto Parts Place (.com), The Parts Bin (.com), Buy Auto Parts (.com) or Parts Discount Warehouse (.com)?

[steviej]

Bank 1 Sensor 1 is the sensor between the exhaust manifold and the cat in the bank of cylinders next to the firewall....correct.

This sensor went on my 02 ES just shy of 40k miles. This was replaced by the dealer under warranty. They did determine (off the car) that the sensor was faulty and had to be replaced. They did say that they have had a "bad batch of these sensors". I didn't pay it any mind because it was fixed under warranty.

Bank 2 Sensor 1 (same spot in the bank closest to the radiator) went at around 60k miles. This one cost me $225 from the closest Toyota dealership to me and I replaced it myself. I just replaced it outright and didn't even bother to test the questionable sensor off the car.

That brings me to my next question: the sensor that is removed, have you checked it to see if it is in fact faulty? There are procedures for this in Lexus shop manuals. In some instances, there are other reasons that will set off O2 sensor or AF sensor codes and not in fact be the sensor itself.

You really can't compare O2 sensors from cars previous to 1996 to post-1996. I say 1996 only due to the uniform adoption of OBD-II in 1996. My current ES has four such sensors. With current emission requirements, O2 sensors and AF sensors are required to operate within much narrower margins.

My previous 1993 SSEi had 1 and it would have cost $30 to replace had it failed.

steviej

[McGuyver]

Thanks for the information.

I will check for cracks or leaks at the rear manifold this weekend.

I replaced the firewall sensor last night with a Denso unit I purchased for less than $200 online (AAA-Import Parts). The unit was marked as an oxygen sensor, but the seller confirmed that this replacement unit will work without a problem. I hope so.

I still have the old sensor on my work bench and I would like to verify that in fact the sensor is bad. Of course, if the CEL/TracOff light goes out, then that would be confirmation enough.

I am still curious though how a sensor could fail in less than 30K miles. SHould I be checking something else?

And...

I am concerned that this sensor may have been bad for longer than I have been led to believe. How long can you continue to operate the car on the default settings without causing other problems? What can I expect to happen...or am I just being paranoid?

[Toysrme]

OK.

The o2 sensor won't cause engine damage. They can't affect fuel changes enough to do much more than give you crappy gas mileage & raise emessions.

It could have just been a rare defaulty sensor, or it could have been killed with some kind of engine treatment.

In general, if your gas mileage doesn't suck & you can pass emessions, there's nothing wrong with o2 sensors. Change them every 100-120,000 m as preventative maint along with the cat convertor<s>.

The only way to test oxygen sensors to time how long it takes them to reach operating temp at a constant 2,500rpm, or throuh normal crank & drive (Idling to let an engine warm up is horrible), and watch their output & watch how fast they respond.

You can't test them by resistance, it's just grab a voltage meter & watch their output :\

You can, however, unplug the o2 sensor & connect up to one of the diagnostic ports (if you know the pins) & test the resistance across the oxygen sensor heater circuit.

The rest of that just really *BLEEP*es me off.

Quit going wherever you're going to get your work done... They're ripping your sclong off & beating you with it. $675 to change an oxygen sensor my !Removed!. They better have thrown in some seriously disturbed sexual favors for $675... You wiggle your arm down the firewall, unplug the wire & take it off with a deep well socket, or a wrench.

You're talking something that takes a half an hour at most, and that's just giving the exhaust 20 min to cool down!!! It takes 5-10 min to do if you put a glove on & just do it. Maybe 10-15 if you splice a new one in.

Generic Bosch splice in oxygen sensors for your engine run around $70usd. The same Bosch sensor with the correct pigtail on it (plug & play instead of splice in) runs about $90-110usd.

The actual Denso o2 sensor runs anywhere between $150-$230usd.

[McGuyver]

OK.

The o2 sensor won't cause engine damage. They can't affect fuel changes enough to do much more than give you crappy gas mileage & raise emessions.

It could have just been a rare defaulty sensor, or it could have been killed with some kind of engine treatment.

In general, if your gas mileage doesn't suck & you can pass emessions, there's nothing wrong with o2 sensors. Change them every 100-120,000 m as preventative maint along with the cat convertor<s>.

The only way to test oxygen sensors to time how long it takes them to reach operating temp at a constant 2,500rpm, or throuh normal crank & drive (Idling to let an engine warm up is horrible), and watch their output & watch how fast they respond.

You can't test them by resistance, it's just grab a voltage meter & watch their output :\

You can, however, unplug the o2 sensor & connect up to one of the diagnostic ports (if you know the pins) & test the resistance across the oxygen sensor heater circuit.

The rest of that just really *BLEEP*es me off.

Quit going wherever you're going to get your work done... They're ripping your sclong off & beating you with it. $675 to change an oxygen sensor my !Removed!. They better have thrown in some seriously disturbed sexual favors for $675... You wiggle your arm down the firewall, unplug the wire & take it off with a deep well socket, or a wrench.

You're talking something that takes a half an hour at most, and that's just giving the exhaust 20 min to cool down!!! It takes 5-10 min to do if you put a glove on & just do it. Maybe 10-15 if you splice a new one in.

Generic Bosch splice in oxygen sensors for your engine run around $70usd. The same Bosch sensor with the correct pigtail on it (plug & play instead of splice in) runs about $90-110usd.

The actual Denso o2 sensor runs anywhere between $150-$230usd.

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I stopped that after the first sensor went out ( firewall side ) I replaced the front (radiator side) about a year ago along with the one after the cat. The dealership didn't even give me the jar of vaseline to ease my pain when I purchased those.

Don't have to worry about them working on this car.

Thanks for the advice.

I am pretty good at the old school stuff, but I just haven't worked with the heavy electrically monitored systems much.

Thanks again.

[Toysrme]

Ya it's cool, it just *BLEEP*es me off when they really overdo it ya know?

I understand it when someone pays like a $90 labor charge when it should be $60, you can reason that kind of stuff with (Well I felt beter about it, or they gave me a pimp loaner car trying to catch my intrest with it). But that kind of stuff is uncalled for. :\

Don't worry about electrical stuff. It's really easy. 90% of the electronics are simply there to check parts & normally, if they don't exactly identify the problem, you can look up what common causes are & narrow it down to a few things.

Much, much easier to troubleshoot. =)

I know a lot of old school people that can't deal with any amount of electronics. it's really sad, because there really isn't much to understand - you don't actually *need* any electrical know-how.

Besides, the mean time before failure of electronic parts is indefinate & electro-mechanical parts many times that than all-mechanical parts.

All you need is a multi-meter (that can read voltage, and check resistance), and book to tell you what causes what problem & what the factory specifications are.