Can anyone tell me what code P0135 means. AutoZone hooked up to my car and this is the code they read. They claim the malfunction exists in the heater circuit for oxygen sensor 1 in bank 1. I was told not to believe what AutoZone always tells you.

 

they are not lying, that's really what code PO135 means.

 

indeed...

means the O2 sensor mounted right near the engine is faulty

(been there, replaced that)

 

if i don't replace it right away will it effect the performance of the engine?

 

The heater in the O2 sensor heats the O2 sensor element so it will read the exhaust quicker so the computer can lean or richen the mixture for best economy and performance faster than by letting it heat up on its own. I would think as long as the O2 sensor itself is working ok there shouldn't be a problem. The worst case is that your cat. converter will get possibly a little more richer mixture going through it during warm up and that is not too good for it.
I would look into having it replaced. Depending on where you live, (I live in California) it most likely won't pass the smog test if your computer is getting any codes.
Hope this helps.

 

it will effect fuel economy as well as emissions...

get it done, it's a relatively cheap fix ($100 i think)