A/F Sensor (Bank 1 /Sensor 1) 02 Camry
 

Hi, I have 2002 Toyota Camry LE and having engine check P1135 and P1155 code. I believe P1135 is for Bank 1/Sensor 1 which is the rear of the engine. Is anybody know if I can change this sensor underneath or above the engine? I cant find any video from youtube for a Toyota Camry only. Thanks for your help.

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https://cimg8.ibsrv.net/gimg/www.cam...95bbf93fad.jpg

thanks for this. but I think the illustration or picture is different from my 02 Toyota Camry. I cant find the rear A/F Sensor from the top.

One cylinder bank has the sensor mounted to the exhaust manifold and sticking up straight.

The other bank has the sensor mounted on the top of the converter can (on opposite side of where the exhaust manifold is) and sticking out sideways.

This is a common problem and when you get both 1135 and 1155 at the same time it is most likely not the sensor. The code is actually for a sensor circuit malfunction, not a bad (low/high) measurement. The malfunction is caused by the fact that Toyota likes to use separate grounds for things, especially inputs to the ECM. The Ground for section B (or C?) is to a bolt on the back lower side of the intake plenum. When someone removes the plenum to change spark plugs, valve cover gasket... they often either reattach the ground to the wrong place or (in the case of my car) not at all. You have to pull the airbox, throttle body, a bunch of vacuum hoses and plus and move the injector electrical connections out of the way to remove the plenum. It sounds harder than it is. Take pictures, label plugs with tape and a sharpie. Towards the middle of the plenum, from the left support bracket bolt hole, is the hole for the ground bolt. If the bolt is missing, it should be a M-10, 6x1 mm thread, 11.5 mm length. Attaching the ground fixes the problem right off. If you decide to replace the A/F bank 1 sensor 1: go under the car, spray it down with PB blaster, unplug the sensor, get an O2 sensor socket (hardened steel impact won't round off the 22 mm nut portion) and loosen it a turn. Detach your ratchet from the socket at this time and remove it the rest of the way by hand. There isn't enough room to back it out with the ratchet on the socket, but it comes out fairly easy by hand.

Is this really a problem? YES.
If you ignore it, the A/F (O2) sensor doesn't kick on and goes into default mode, which is fairly rich. It wastes gas, but more importantly, if you ignore it long enough you burn a hole through your Cats. Your 1135 and 1155 errors are replaced with 0420 and 0430 errors the next time you drive 30 minutes. With the front sensors working it will now be able to tell that the Cats aren't. I'll look for a thread on replacing Cats and provide the insight on what I've learned about that repair. Spoiler, you CAN remove the back Cat from under the car without a lot of disassembly.