Check Engine/trac Off Light On

[bxf]

I have a 2000 EX300. The car got a check engine/trac off light on problem recently. I took it to auto zone for reading the code. The code showed P0171 system too lean bank 1. The guy who did test for me told me that the problem is the defective O2 sensor. He also showed me the sensor which is just right in front of engine.

I bought the Bosch universal O2 sensor from oxygensensorwholesale.com which costs me $68. The sensor looks exactly same as original one. It comes with 2 black wires, 1 blue wire and one white wire, and also comes with a kit for making connection with the old plug. After replaced new sensor I disconnected the battery for 10 minutes to reset the code. It seems to be fine when I restart the engine because check engine and trac off light went away.

It is less than 12 hours. The check engine and trac off light comes back on again. I really don’t know what is going on now. :( Maybe I should buy OEM sensor? Maybe I replaced wrong sensor? Or maybe some problem else involved? I remember the reprehensive did mention me that there two O2 sensors before catalyst when I placed order. Should I replace both of them? I really need help to figure out the difficult. I appreciate any info.

Thanks

[steviej]

The sensor he pointed to in the front of the vehicle is Bank 2.

Bank 1 is the rear bank, next to the firewall.

Keep in mind to that air fuel sensors (A/F) are between the exhuast manifold and the catalytic converter.

O2 sensors are the ones after the cat and are usually accessable from under the vehicle.

steviej

[coolchicky]

This is from my post on Oct. 20, 2006 regarding a similar issue:

Update: My mechanic pulled a diagnostic trouble code of P0446 which relates to a service bulletin regarding a "false M.I.L. 'ON' DTC P0446 on some 1999 year ES 300's". The bulletin covers a certain VIN range which mine happened to fall under. This calls for the addition of Vacuum Control Valve (PN 25852-20010) which requires .5 hours. My dealer ended up charging me for 1.0 hours. They said the job was a bit more complicate than originally quoted. After waiting an hour already I gave them the go ahead (incompetent mechanic I suppose). Anyway, the part cost $34.09. I'll keep the forum posted if problems persist.

There is another recent thread regarding this problem...do a search, it might help.

[bxf]

steviej, Thanks for your fast response. I may try to replace the one in rear bank by myself. Is that hard to locate and reach for that sensor?

Meanwhile, I'm still wondering what the guy said. Is code P0171 mean defective air fuel sensor? Or, some thing else?

Thanks

[steviej]

steviej, Thanks for your fast response. I may try to replace the one in rear bank by myself. Is that hard to locate and reach for that sensor?

yes. best if you have a long arm and the engine is cold. Put some liquid wrench on the base and threads of the A/F sensor before attempting to remove... it helps.

Meanwhile, I'm still wondering what the guy said. Is code P0171 mean defective air fuel sensor? Or, some thing else?

According to the FSM, P0171 is obtained when air fuel ratio feedback is stable after warming up engine, fuel trim is considerabley in error on RICH side (2 trop detection logic)

Trouble Areas:

- Air Intake hose(hose loose or cracked)

- Fuel line pressure

- Injector blockage (cylinders 1, 3 or 5)

- Open or shor in A/F sensor circuit

- Intake air flow meter

- EFI engine coolant temperature sensor

- Gas leakage on exhaust system

- PCV hose connection

There is a hole diagnostic flow chart to help determine the exact trouble point.

steviej

[MKLEX]

I had similar problem. My Check engine and TRAC lights were ON. Computer found error in Oxygen sensor. I have replaced it and lights went OFF. However, I still feel less power in the engine. Mechanic told me that I should replace air fileter more frequently.

I was thinking about cleaning the intake with cleaner, but I'm not sure if this would help.

Any suggestions?

[Lexlogic]

steviej, Thanks for your fast response. I may try to replace the one in rear bank by myself. Is that hard to locate and reach for that sensor?

Meanwhile, I'm still wondering what the guy said. Is code P0171 mean defective air fuel sensor? Or, some thing else?

Thanks

I have the same car/year and problem you have. Try to clean Intake air flow meter. The part is after the air filter secured by two screw and electrical plug attached. Unscrew and take out for cleaning and also check the airfilter could be drity. Then reset ECU and let know if the problem when away.

[bxf]

Thanks all. I just replaced A/F sensor in bank 1. It was harder to reach than the one at front. After the work done, same thing happened again after a couple of days. Before I replaced the sensor in bank 1, I did clean up the air flow sensor which Lexlogic mentioned. Now I just noticed that there is a broken part on the rubber seal along the air filter, which was replaced not to long ago. Is that possible the broken part on the air filter cause too much unstable air flow intake? Any way, I’m going to replace it and see what is going on.

[Aikibro]

I have the same issue with my check engine/trac lights on my 97...do you guys know if the above steps for the '00 would be the same? Thanks.

[rikishah]

I have a check engine light come on a few weeks ago so I freaked out and took it to a local mechanic who said it was bank 1/sensor 1 for heat. Then today, I accelerated to quickly in a wet conditions and now my TRAC off light is on also. :( Is this an expensive repair? I looked around and some are related problems, and also a canistor? What's that?

[djspawn00]

I have a check engine light come on a few weeks ago so I freaked out and took it to a local mechanic who said it was bank 1/sensor 1 for heat. Then today, I accelerated to quickly in a wet conditions and now my TRAC off light is on also. :( Is this an expensive repair? I looked around and some are related problems, and also a canistor? What's that?

Do you know what code your getting? (autozone will scan for free) The traction control light is nothing to worry about usually. It just comes on with the check engine light, its toyotas way of saying, "hey fix this" rockauto.com and oxygensensors.com sell the o2 sensors for a good price, and they're not hard to change usually.

[rikishah]

I have a check engine light come on a few weeks ago so I freaked out and took it to a local mechanic who said it was bank 1/sensor 1 for heat. Then today, I accelerated to quickly in a wet conditions and now my TRAC off light is on also. :( Is this an expensive repair? I looked around and some are related problems, and also a canistor? What's that?

Do you know what code your getting? (autozone will scan for free) The traction control light is nothing to worry about usually. It just comes on with the check engine light, its toyotas way of saying, "hey fix this" rockauto.com and oxygensensors.com sell the o2 sensors for a good price, and they're not hard to change usually.

My local mechanic told me it was the P1035 I think code. Something related to heater air flow bank 1 sensor 1. I've been looking around, and it seems pretty expensive. Almost $200 or so. I also have a $75 Lexus Dealer gift card from their card services, so my assumption would be that labor would be free for and I'd just pay for the part. What do you guys think?

[rikishah]

Actually it is the P1135 heat sensor. Bank1, sensor 1.

[djspawn00]

hmmm you might need an air/fuel ration sensor.

[rikishah]

I just went to Autozone to verify and it is the P0135 sensor, which is the heat sensor. I saw a few diagrams in a thread, but still wondering where it is located. I also know that for sure it is the bank 1, sensor 1 heat sensor. It is suppose to be next to the firewall, but where is the firewall? lolThanks guys!!

[mburnickas]

what the $$^^*#& sensor do you need? Is it P1035 or p1135.

I asked this forum the same question (diagrams) on help and got ZERO..nice ha.

P1135 code is for the firewall sensor (B1 S1). It is around $177 OEM from dealer. I know this since I did mine last week. PITA to get too.

[rikishah]

its P0135 sensor. Heat sensor bank 1, sensor 1 lol hahah

[Dave H.]

Everyone keeps saying the Bank 1 Sensor 1 is the one in the back of the engine by the firewall, but according to my Haynes Manual it shows it as the one in front near the radiator (Pg 6-18).

Can someone please clarify as soon as possible since I have an Oxygen Sensor here ready for install and I was about to put it in the front

Thanks

Dave

[way2007]

Hi All,

I am in the same boat. I have a 1999 ES300 and I get a p1135 and it says Bank 1 sensor 1 air/Fuel ratio sensor. Where is it actually located on a 1999 model? The 1997 manual show its on the Front. But i see posts mentioning its at the back near the firewall. Please advise, i have a failed emisstion test and need to fix it in 5 days. :cries:

thanks

[camlex]

bank 1 is at the rear of the engine bay, in the manifold closest to the firewall. Bank 2 is in the front nearest the radiator.

Also, it's good idea to change both at the same time. Dealer cost is ~$110.( Both sensor are same.)

Hope that helps.

[way2007]

bank 1 is at the rear of the engine bay, in the manifold closest to the firewall. Bank 2 is in the front nearest the radiator.

Also, it's good idea to change both at the same time. Dealer cost is ~$110.( Both sensor are same.)

Hope that helps.

Thanks for your reply. i just have the a/f sensor that i got from junk yard from a 2000 yr model.lets see if that works. if it doenst i will go buy the part from the dealer. do you know any specific dealer that sells it for 110 or the partnumber for it?

[way2007]

i was just told by a part supplier that the 1999 es300 car with california emission have A/F ratio sensor for bank1 sensor1 in the Firewall location. But for all other locations the 1999 es300 model A/ F ratio sensor for Bank 1 and sensor 1 is located in the front near the radiator. Also he mentioned that the a/f sensors for Bank1 and bank2 locations are not the same part number/type.

Can someone please confirm if both are true.

I just bought the A/F sensor from firewall location of a junkyard car. so i guess i cant use it now at the front location!! :(

[way2007]

i was just told by a part supplier that the 1999 es300 car with california emission have A/F ratio sensor for bank1 sensor1 in the Firewall location. But for all other locations the 1999 es300 model A/ F ratio sensor for Bank 1 and sensor 1 is located in the front near the radiator. Also he mentioned that the a/f sensors for Bank1 and bank2 locations are not the same part number/type.

Can someone please confirm if both are true.

I just bought the A/F sensor from firewall location of a junkyard car. so i guess i cant use it now at the front location!! :(

Also, The A/F sensor i got from another junk yard es300 firewall location ( not sure of the model) is 89467-41030 . Will this work on my 1999 ES300 ?

thanks