Trouble code p1135 for the A/F sensor. I have a 2001 3.4L 4runner with 149000 miles. I just changed my timing belt, water pump, both belt pulleys, and thermostat all myself. Drove about 100 miles and everything was running great and then my check engine light came on. I have checked everything I touched while doing the work. Nothing seems wrong. I cleaned the mass air flow sensor and changed the air filter (pretty dirty). Could this be just a fluke that it the A/F sensor went out right after all the work I just did? Any suggestions? Thanks.

Have you ever replaced this sensor?? I say fluke!
Clear the code and wait for it to come back, at that mileage the sensors tend to get sticky. Unless you have a computer to drive the truck and monitor the sensors movement,clear the code and let the system set the code again. Light comes back same code,replace the sensor

Thanks for the response. I went to autozone last night and they pulled the P1135 and cleared it for me. I made it half way out of the parking lot and it came back on. Had them check it again and same code. Went home sprayed the air flow sensor with cleaner unplugged the battery to clear the code (I think that is all I have to do to clear the code myself?). Drove for 30 seconds and check engine light came back on. One thing that I had to do while changing the timing belt was reposition the cam shaft pulley to realign timing mark. It slipped while putting the new belt on. I don’t think this would have hurt anything. I also turned the engine by hand a lot to assure all marks were lined up. Can you turn it too much?

Sorry forgot. No i have never replaced the sensor.

This is an emmisions code so i doubt the t-belt had anything to do with it. When you put it back together were all the timing markings in the correct place?
If so just replace the sensor. Punch the code into the search it has come up a lot and i think people have reported problems w/aftermarket or the wrong sensor lasting a short period of time.

P1135 is the A/F sensor heater circuit. Very specific--it has to be the sensor or the wiring--and you would have to be a real F/U to mess up the wiring doing a TB. It's all at the other end of the engine on the exhaust pipe and goes rearwards to the ECU. Cleaning is beyond useless--you can't heal a fried heater. Get a new OE Denso sensor off of Amazon and call it a fluke. Get the Denso part number here: Linky and then search Amazon (or just Google it).

CHALK IT UP TO

All the timing marks were dead nuts on. One odd thing is that after lining up the pulley marks with the marks on the engine and then lining up the belt marks with the pulley marks I rotated the crank a couple of times and the marks on the belt were off at all three pulleys by 3 teeth. The belt slipped on all pulleys by the same amount. I rotated the crank a lot more and the marks stayed were they were at. Since the pulley marks still lined up with the marks on the engine I disregarded the belt not lining up. The engine seems to run great and have no timing issue.

I believe my next step will be ordering the sensor. I may try to check the sensors resistance off the truck using a blow torch. You guys ever have any luck doing this? I really don’t have a clue what I am doing. I just read as much stuff as I can on line and I also have a copy of the FSM. I am pretty anal about following any of the instructions I use. I know I am probably more careful than the dealer mechanics.

just got that code too at lunch when i stopped by to see what codes were lurking on my computer....the usual:

P0125
P0141
P1135 (i just learned this is a California Specific application - and im in SC) how do i disable completely?

just got that code too at lunch when i stopped by to see what codes were lurking on my computer....the usual:

P0125
P0141
P1135 (i just learned this is a California Specific application - and im in SC) how do i disable completely? or can that even b done?

I don't guess you can unless you fix it.

that sucks. did u find a good place where to get one?

The the post above by "TheDurk" has a link to the denso website where you can look up your part number. Then search for it on google. I found mine here Amazon.com: Denso 234-9002 Oxygen Sensor (Air and Fuel Ratio Sensor): Automotive

wtf. thats ridiculous. 103$?! i think ill pass for now. i need sliders and tires.