Question

P1135 and P0300, 0301, 0302, 0303, 0304 codes on the 2001 Rav4 after I have replaced the cat which had been throwing codes P0420 and P0430.They have now gone out but now I have those other codes P1135, P0300, 0301, etc. And the engine is not running like it should now. I undesrtand that the A/F sensor is very rarely the real issue and everything was running fine until I put the Dorman cat I bought from CarQuest. Where do I go from here? Thanks, Andy

Answer 1

P1135  A/F (airflow) sensor heater circuit malfunction

The A/F sensor will not cause a misfire code condition,the misfire codes can cause P1135. You are going to have to look for the cause of the misfire, you may want to check to see if the cause is from excessive back pressure start by removing the upstream  02 sensor (even though this is a A/F sesnor) and leave it plug in clear the code and restart, if the misfire return the catalytic is not the problem. If it is not the catalytic reinstall the sensor and disconnect it, Retest and check for misfire ( disconnecting the 02 sensor will cause the CK ENG LT to illuminate) if the misfire is present  you can be sure the 02 are not the cause, check mechanical condition such as a open EGR. If mechanical condition are ruled out the ignition system needs to be check for its proper power supply to the ignition coil,  The vehicle at this year make and model are known for its ECM problem that cause early catalytic failure and misfire symptoms