Cel Code Confusion

[Topshelf]

Hey guys, CEL/VSC just came on yesterday so I stopped at AutoZone today to have it checked out. Turns out it's the P1135. So I hopped on here to do a search, and what I'm finding is totally different from what the computer listed.

Here's what I'm finding on here...

P1135 (Air/Fuel Ratio Sensor Heater Circuit Malfunction Bank 1 Sensor 1)

But here's what the computer at AutoZone called a P1135 for a 2002 RX300 AWD...

P1135 (Pedal Position Sensor A Circuit Intermittent)

So what is the deal? Anyone know why mine is so different from the rest? I'd like to fix this thing immediately, but I don't even know what to do since these codes are so different.

Any help here would be great. :)

[RX in NC]

When my wife's 2000 RX300 threw a P1135 trouble code in August 2004, it did indeed point to a failing Air/Fuel Ratio Sensor. That sensor was replaced under a goodwill warranty by our local dealership and the problem was fixed and has not returned. To confirm your experience, know that I also had the trouble code read at AutoZone before I contacted the dealership and AutoZone's interpretation of the P1135 trouble code was as a "Pedal Position Sensor" issue, just as yours was.

But it is well-known on this forum that trouble codes P1135 as well as P1130 both point directly to the Air/Fuel Ratio Sensor, which is also commonly called the Bank 1 Sensor.

For further peace of mind before you proceed with repairs, you may want to call your local Lexus dealership, tell them that you've thrown a P1135 trouble code, and confirm that it does indeed indicate a failure associated with your Air/Fuel Ratio Sensor.

Good luck and report back here with what you find out. I fully believe that replacing the Air/Fuel Ratio Sensor will fix your problem.

[Topshelf]

Thanks man! I just went to a different AutoZone to have the code read again because it seemed so odd, and it was the correct reading P1135 - Pedal Position Sensor. I started to think it might be the cheap $35 Throttle Position Sensor, but all the reading on here does point to an O2 sensor. I'll call Lexus up today to verify, but I'm assuming that replacing the O2 sensor under the car, before the cat, will fix this issue.

Again, thanks again for the reply.;)

[Topshelf]

Hey RX, just wanted to thank you for being the only person to help out here. Guess everyone else was too busy. :(

Anyway, I replaced the suspected O2 sensor and everything is now working perfectly again.

Thanks again. B)

[tvkel]

Topshelf-

Did you have the check engine light and VSC light on at the same time? I too got the dreaded P1135 code and had the same questions about the Autozone (pedal sensor) diagnosis. Which O2 sensor did you replace? I am VERY new to this and I don't know if this is one I should attempt by myself. I have noticed my SUV is running at a higher RPM and is idling funny. Did you have this problem too?

Thanks,

tvkel

[Topshelf]

Yep, check engine and VSC both came on at the same time. However I didn't have the high rpm and idling issue. I seriously thought about replacing the Throttle Position Sesnor first since it was only $35. Figuring with nearly 75k miles, it wouldn't hurt. But after tons of reading and RX's advice, I went with the O2 sensor. I believe they call it Bank 1 Sensor 1, which basically is the pre-cat sensor under the truck. There's 2 pre-cats...1 under the truck and 1 infront of the radiator. Ofcourse it's the one under the truck that needs replacment. LOL Actually it wasn't bad at all. My only concern was stripping the threads as I read a few people had that problem, but there really isn't much you can do to avoid that. I simply rode the truck up on ramps, blocked the tires and put jack stands under it for security. Took all of about 2 minutes. Crawled under there and sprayed the sensor with some lubricant in hopes of it penetrating into the threads, but I seriously doubt it did anything then went up top and removed the EFI fuse to reset the codes. Came back 20 minutes later with a breaker bar and the sensor socket and crawled back under the truck. First reach up there with both hands, squeeze the release lever on the connector with your left and pull the other side to free the connector. Then pop that socket/breaker bar on, say a quick prayer and push toward the front of the vehicle to unscrew the sensor. Mine was pretty tight, but once it budged it just unthreaded very easily. Too easily I thought. But after inspecting everything there was no thread damage. So I put the copper anti-seize on the new sensor, threaded it in, tightened it up and plugged it in. Reinstalled the fuse, closed everything up and started the truck up. 250 miles later, no lights and everything seems normal. :) It sounds a lot worse than it really was. Infact, it was one of those jobs that after you do it, you're like "That was it???"

One quick note is that the exhaust should be at ambient temp, so make sure it's only running for a few seconds to get it up on the ramps if you go that route.

I bought the sensor and the socket here. Sensor Part Number is Denso 234-9009. Don't waste your money on anything else, many issues with the cheaper sensors. And after you add it to your cart, you'll see an option for the socket. I called to verify the size, and apparently 99% of the sensors are 22mm, so that socket is the correct one. I bought the kit since I like to have as many options as possible for unknown projects, but you won't need anything more than the socket for this job. Oh yeah, mine is a 2002, so if yours is a different year, you might want to verify that part#, but I'm sure it's the same since the motor is the same.

Good luck, and let me know how it turns out for you.

[tvkel]

Thanks for the help! Got the part from the Lexus Stealership (needed to get it done) $282 part number 89467-48011. I am about the replace it with my Dad's help. Here is his question... Why do we need a special Socket? Can you not just use an open-end wrench? Please let me know as soon as possible. The link you had set up to order the kit took me to a page that didn't exist any longer. Do you know the web address so we can at least see a picture of said socket? Just want to make sure we have all we need in place before we start this project.

Thanks a million!

tvkel

[Topshelf]

Dam! For $180 you could have had the sensor and the socket in 3-5 days. Oh well. As far as the socket goes, it's just a standard 22mm O2 Socket you can buy from any auto parts store. For the $10 they charged, it was worth it to me not having to fight with a wrench. And now that I think about it, I needed a breaker bar on that socket just to get it to turn. It's up to you, but it's only a few more dollars at this point.

Oh, that link thing is wierd. It's supposed to point to www.oxygensensors.com

[scw11]

Yep, check engine and VSC both came on at the same time. However I didn't have the high rpm and idling issue. I seriously thought about replacing the Throttle Position Sesnor first since it was only $35. Figuring with nearly 75k miles, it wouldn't hurt. But after tons of reading and RX's advice, I went with the O2 sensor. I believe they call it Bank 1 Sensor 1, which basically is the pre-cat sensor under the truck. There's 2 pre-cats...1 under the truck and 1 infront of the radiator. Ofcourse it's the one under the truck that needs replacment. LOL Actually it wasn't bad at all. My only concern was stripping the threads as I read a few people had that problem, but there really isn't much you can do to avoid that. I simply rode the truck up on ramps, blocked the tires and put jack stands under it for security. Took all of about 2 minutes. Crawled under there and sprayed the sensor with some lubricant in hopes of it penetrating into the threads, but I seriously doubt it did anything then went up top and removed the EFI fuse to reset the codes. Came back 20 minutes later with a breaker bar and the sensor socket and crawled back under the truck. First reach up there with both hands, squeeze the release lever on the connector with your left and pull the other side to free the connector. Then pop that socket/breaker bar on, say a quick prayer and push toward the front of the vehicle to unscrew the sensor. Mine was pretty tight, but once it budged it just unthreaded very easily. Too easily I thought. But after inspecting everything there was no thread damage. So I put the copper anti-seize on the new sensor, threaded it in, tightened it up and plugged it in. Reinstalled the fuse, closed everything up and started the truck up. 250 miles later, no lights and everything seems normal. :) It sounds a lot worse than it really was. Infact, it was one of those jobs that after you do it, you're like "That was it???"

One quick note is that the exhaust should be at ambient temp, so make sure it's only running for a few seconds to get it up on the ramps if you go that route.

I bought the sensor and the socket here. Sensor Part Number is Denso 234-9009. Don't waste your money on anything else, many issues with the cheaper sensors. And after you add it to your cart, you'll see an option for the socket. I called to verify the size, and apparently 99% of the sensors are 22mm, so that socket is the correct one. I bought the kit since I like to have as many options as possible for unknown projects, but you won't need anything more than the socket for this job. Oh yeah, mine is a 2002, so if yours is a different year, you might want to verify that part#, but I'm sure it's the same since the motor is the same.

Good luck, and let me know how it turns out for you.

Topshelf,

just want to thanks you for the detail info of this problem, i just follow your instruction to change my bank 1 sensor 1 ($170 from oxygensensors.com ) today, and VSC and CEL is off now. i love this forum because people always willing to provide the help when there is a problem.

scw11