P1135 code clarification

[gilby4runner]

I have searched but i need a few things spelled out to me. My runner (2002 Sport) threw the code yesterday and i hit the forums looking for answers. I have run across a few things that i need to clarify.
1. The front (O2 sensor) is now called the A/F Sensor?
2. Should this be an opportunity to go ahead and change out the rear sensor while i am at it or will it make a difference?
3. I am going back with toyota parts. The wonderful assistant at Autozone tried to explain to me that bosch would be best and that the toyota dealer will just sale me a bosch sensor but at a higher price. He didnt take to kindly to my laughing in his face at that point. Any reasonible places to buy a new one?
4. Anything else i should do while i am at it?

Thanks guys!

[YotaFun]

Yeah when I came across my searches this is what I found.
http://www.tundrasolutions.com/forums/sienna/59335-code-p1135/

I gather you came across it as well.

If you want you can change the rear o2 sensor as well, not really needed unless it is going bad but if ou do it now this way you won't have to worry abou I going for a while.

Northridge Toyota could probably hook you up.
If not I gt a discoun from the toyta dealer near me through the school I you want to shoot me a pm that's cool too.

[corax]

before you replace anything, try just disconnecting and re-plugging the connector - sometimes that all it takes - alot of DTCs or codes are set by poor/dirty/intermittent electrical connections, the ECM has no way of telling a harness issue from a sensor issue. If the DTC comes back, then replace the sensor

BTW, all 4 wire O2 sensors work pretty much the same, and while I would never put a set of Bosch plugs in my 'yota, I would and have put a Bosch O2 sensor in it with no problems - just have to splice the wires onto the factory plug (DO NOT SOLDER THESE WIRES - some O2 sensors get their oxygen reference through the wire insulation - if you flow solder through the wire, you'll stop that from happening - use a butt connector with a good wire crimper and some shrink wrap)

[YotaFun]

eek I would never do any wiring modification to any o2 sensor wiring, that is just calling for trouble.

Bosch makes a factory replacement for the Yota's, however I will be switching back to ones from Toyota, cause the Bosch I got did not match the one that came out, at least in the front, which make me believe why my gas mileage is so stinky.

Also when you go to unplug and replug, get some electronic connector cleaner and just squirt those plugs clean.

Is still find this an interesting way for the computer to tell if the o2 sensor is bad. When mine went I got a P0*** not a P1***. It wasn't a manufacture specific code like the one he is getting.

[gilby4runner]

corax-
my light came on then went off and has stayed off. I got up under the runner and checked the connections. ( I had issues with my 02 connection on my jeep) Everything was connected well and was surprisingly clean.

My biggest concern was neededing an AF sensor and not the 02sensor. That confused me a little. There is only one sensor before the cat. (A/F) and one after the second (O2). I agree that some Bosch parts are ok but i got 111,000 miles with no issue so i am going back with OEM parts.

Thanks again for the info guys!

[corax]

eek I would never do any wiring modification to any o2 sensor wiring, that is just calling for trouble.


not a modification, just re-using the original connector - the 2 white wires are just heater cicuit so polarity doesn't matter (electric resistive element) - the 2 grey wires are the only ones that I ever got backwards, IIRC the voltage signal was just reversed (voltage went high when I induced a lean condition when it was supposed to go low), so I switched the terminals and everything was fine

a bit more info for future reference:
P1135 Heater Circuit Malfunction. When the heater operates, heater current exceeds 8A or heater current of 0.25A or less. Please confirm heater resistance specification*. This DTC can be set due to other related parts failure. All A/F Sensors are monitored for abnormal heater condition. The ECM checks the amount of current required for the sensor heater. If the current is too high or too low a DTC will be set. If the current level detected is too high, the ECM will shut off the heater. The ECM provides a pulse width modulated control circuit to adjust current through the heater. -- looks like an open circuit or short to ground on the O2 heater can cause this (under- and over-current respectively)

If the light has gone out and not come back, I would wait for a second occurence before spending the cash - like I said, might have just been an electrical connection -- I can understand using the OEM parts though (it's nice to get a new connector and know it's wired right)

[gilby4runner]

Cleared the code and it came back 3 days later. I went to a local body shop and talked them into ordering the part for me. I got a facotry part at about 30% off dealer cost. While i was at it i went ahead and ordered another mast for the radio...tired of CD's.

Thanks for all the help and info!

One more question- since installing the new sensor and reconnecting the battery i have noticed my idle is at 500 rpms. It did this last time i changed the battery and i know it will eventually go back to normal but man i like how quiet and smooth it is at 500. Oh well

[YotaFun]

Cause when you take out the battery, in a sense your resetting the ECU back to factory specs and it has to relearn all your habits and the conditions aroudn you.

I know its a beautiful thing though, makes you feel like your getting the truck right off the lot, well, almost...

[MTL_4runner]

I have searched but i need a few things spelled out to me. My runner (2002 Sport) threw the code yesterday and i hit the forums looking for answers. I have run across a few things that i need to clarify.

1. The front (O2 sensor) is now called the A/F Sensor? Correct

2. Should this be an opportunity to go ahead and change out the rear sensor while i am at it or will it make a difference? In a nutshell, the front sensor provides the input for the computer to adjust fuel, the rear sensor tells you if the converter is working properly....so no it won't help.

3. I am going back with toyota parts. The wonderful assistant at Autozone tried to explain to me that bosch would be best and that the toyota dealer will just sale me a bosch sensor but at a higher price. He didnt take to kindly to my laughing in his face at that point. Any reasonible places to buy a new one? If he were selling Denso parts, I might buy that story but definately do not use Bosch parts on these trucks (only Denso or NGK for replacement electronic parts). Northridge Toyota or Toyota of Dallas are the best for OEM stuff I've found.

4. Anything else i should do while i am at it? Clean the MAF sensor with brake cleaner and pull the negative battery terminal for 5 mins to reset the ECU. That will reset everything and get you back to your best MPG quickly.

Thanks guys!



See answers in red above.

[MTL_4runner]

Bosch makes a factory replacement for the Yota's, however I will be switching back to ones from Toyota, cause the Bosch I got did not match the one that came out, at least in the front, which make me believe why my gas mileage is so stinky.

Is still find this an interesting way for the computer to tell if the o2 sensor is bad. When mine went I got a P0*** not a P1***. It wasn't a manufacture specific code like the one he is getting.


Few comments....

1) It wouldn't be the first time a Bosch O2 sensor was the cause of bad MPG in a Toyota truck. Best advice I can give is don't use Bosch parts in these trucks. If you don't want to use OEM from the dealer, at the very least, make sure you get a Denso brand sensor (which is who makes the OEM sensors).

2) The reason why one got a P1*** code and another got a P0*** code for the sensor is that the P1*** is the code for an A/F sensor and the P0*** code is for a standard O2 sensor. Keep in mind these sensors are not interchangeable and actually function quite differently.

[YotaFun]

Thanks for the clarification Jamie, and the tip on the Denso brand sensors, I will be hitting up my Toyota Dealer tomorrow.

However I have a question cause I am somewhat confused.
My ECU threw a code for the front 02 sensor that too was a P0*** code.
It was not a Manufacture specific code like this particular code was.
So in turn I gather that ,on the 01&02 at least, the front 02 sensor changed for just a standard 02 to a A/F sensor?

I just would like to understand correctly

[MTL_4runner]

However I have a question cause I am somewhat confused.
My ECU threw a code for the front 02 sensor that too was a P0*** code.
It was not a Manufacture specific code like this particular code was.
So in turn I gather that ,on the 01&02 at least, the front 02 sensor changed for just a standard 02 to a A/F sensor?

I just would like to understand correctly



In 1999 the front sensor changed from an O2 sensor to an A/F sensor. The sensor after the converter on all years 96-02 will be a standard O2 sensor. So for 96-98 trucks with a bad front O2 sensor I would expect to be getting a code P0135 (example) and for 99-02 trucks with a bad A/F sensor, I would expect to see a code P1135 (example) through the OBD system.

[MTL_4runner]

I forgot to mention that another great source for inexpensive sensors is URD.
http://www.urdusa.com/index.php?cPath=9_13&osCsid=aqm4g2go5utc36u1v251a57sd2

They carry the Denso brand sensors, just make sure to verify the part number you need before ordering.

[YotaFun]

However I have a question cause I am somewhat confused.
My ECU threw a code for the front 02 sensor that too was a P0*** code.
It was not a Manufacture specific code like this particular code was.
So in turn I gather that ,on the 01&02 at least, the front 02 sensor changed for just a standard 02 to a A/F sensor?

I just would like to understand correctly



In 1999 the front sensor changed from an O2 sensor to an A/F sensor. The sensor after the converter on all years 96-02 will be a standard O2 sensor. So for 96-98 trucks with a bad front O2 sensor I would expect to be getting a code P0135 (example) and for 99-02 trucks with a bad A/F sensor, I would expect to see a code P1135 (example) through the OBD system.


thank you for the clarification, I just wanted to make sure I wasn't going insane or something, and you pinpointed the exact code I got before lol!

[Scuba]

Jamie, from reading your post above, is it really safe to clean the MAF with brake cleaner ?

[MTL_4runner]

Jamie, from reading your post above, is it really safe to clean the MAF with brake cleaner ?


Yes, absolutely.....done it many times already. The issue with cleaning the MAF is not to leave any residue on it or the next time the sensor heat up, it will bake the residue onto the sensor wire (over time it would get progressively worse). The brake fluid cleans any dirt, oil or other debris from the wire extremely well and dries leaving no residue at all. If your sensor is dirty, you may notice an improvement in MPG after cleaning. Make sure to reset the ECU after though.