Alright, got random missfire.....idle speed sensor, and O2 bank 1 sensor 1. Any ideas? The miss seems to get progressively worse the higher the rpm. Could it be just plugs? or plugs and wires?

 

Generaly help if you provide the actual codes.

 

P0030 - Heated Oxygen Sensor (H02S) Heater Control Circuit Bank 1 Sensor 1
P0300 - Engine Misfire Detected
P0506 - Idle Speed Low
P0131 - Heated Oxygen Sensor (HO2S) Circuit Low Voltage Bank 1 Sensor 1

 

Would the O2 cause a missfire? When the engine is cold, it seems to run fine. Consequently... .when the engine warms up, and I assume that the system goes closed loop, the missfire starts to happen. I am just wondering what to deal with first, plugs and wires or O2's.

 

P0030 - Heated Oxygen Sensor (H02S) Heater Control Circuit Bank 1 Sensor 1

Could you possibly mean P0135 = B1S1 O2 sensor heater circuit? There is no P0030.

P0131 - Heated Oxygen Sensor (HO2S) Circuit Low Voltage Bank 1 Sensor 1

This means the O2 sensor voltage is staying below 200mV. That erroneously tells the PCM that Bank 1 is running lean, and when it goes into closed loop, it pours unneeded fuel into that bank, probably enough to make it misfire.

You need to figure out whether its a sensor problem or a wiring problem. You could swap the precat O2 sensors side to side and see if the problem follows the sensor (sensor problem) or stays on Bank 1 (wiring problem, or actual engine problem causing low sensor voltage and sluggish warmup of sensor). Or, check the wiring harness to make sure you have +12V being supplied on the heater circuit (brown wire on the harness, pink wire on the sensor). Make sure the black harness wire is providing a good ground.

P0300 - Engine misfire Detected

P0506 - Idle Speed Low

Solve the O2 sensor problem first, that might cure the other two. Or, the O2 sensor problems may be the result of something else, like a complete lack of fuel or a huge amount of excess air on one of the cylinders on Bank 1. Try and rule out the O2 sensors first.

 

Well, i thought that might be the problem. However, I drove it to the store this morning just to test it out, and the miss was happening as soon as I was driving away. No way it was in closed loop that quick... so I bought some plugs to see what happens. Just need to wait for the headers to cool off then I will get down to it. Thanks for the tips.