P0430 Chevrolet - 2007 Tahoe LS

Question

I currently have a P300 and a P430 code stored. My engine is running like on 7 cylynders instead of 8. I am also getting a stabilitrak not working alert which came on when the engine started running badly. I have replaced spark plugs and wires so far with no change. Any suggestions on what to do next?

Answer 1

P0300 Random misfire

P0430 Catalytic below efficiency Bank 2

You still have a misfire condtion if you feel like you are running on 7 cylinders. Misfire conditon occur when a cylinder is not contributing , such as  a mechanical condition , or a fuel injector or even a igntion coil that is not operating. Whenever the CK ENG LT is on the stability trac is turned off, the reason is the vehicle is not operating at manufactuer specification. This year make and model the catalytic convertor tends to plug easy which in turns sets a P0300. You can remove the 02 sensor on Bank 2 Sensor 1 , but leave the 02 sensor connected and secured or it will set a P0300.  and retest the engine for a misfire condtion. if the perfromance improve investigate for a plugged cataltyic.

 A sparkplug condtion is a good indication when a misfire occurs,by comparing it to other cylilnders, there it can help you narrrow down the cylinder.

 Igntion coil are the most suspectable of creating a misfire conditon.