VaughnCo

Hopefully one of you guys can give me some guidance. The check engine light came on in my 05 Z51. It has cam, CAI, Long tubes and one hell of a tune. I do drive it hard. It seems to be running fine, no power loss or hesitations. I did just replace all the plugs and wires a month ago due a plug wire that melted laying on the header. I checked to see if that was the case again but all the wires look good.

P0300 (Random Misfire)
P0030 HO2S Heater Control Circuit Bank 1 Sensor 1
P0135 HO2S Heater Performance Bank 1 Sensor 1
P0030 HO2S Heater Control Circuit Bank 1 Sensor 1
P0135 HO2S Heater Performance Bank 1 Sensor 1

The printout stated that it may be dirty fuel injectors. Any tips you guys can provide to get this resolved with out having to take it to the Dealership would be greatly appreciated.

Mordeth

Check the 02 sensors. Also check the fuse for them in the fuse box. Should also triple check the wires, the coils and the plugs themselves.

irok

you need a new 02 sensor or problem with harness going to that sensor.not uncommon for a car that old

BlindSpot

Driver's side O2 Sensor. Check the harness all the way from the sensor back to the connector at the valve cover. Driver's side is a tough side and you might have touched the harness on a header tube somewhere. If the harness is OK, then looks like the heater might have burned out on the sensor. Replace sensor then.

Random misfire is probably related. If the sensor does not warm up (or not sending a temp signal) to a temp the ECM expects to see at a given ECT, then the performance code is usually set. However, the heater circuit failure indicates there is no heater signal being received and that will be accompanied by the performance failure.

Long story short - harness burned through or sensor failure on driver's side.

VaughnCo

Thank you guys, especially BlindSpot, thats exactly what was wrong. We are all fixed.

corvettenutz

HO2S heater element has failed