P0305 code

[slefler]

Hello everyone,

First off the its an 08 5.3l avalanche with 92,000 miles on it. My problem is CEL with p0305 code and after I clear it if it warm outside it wont come back until it cools off around 35 deg. So far I have replaced the plugs and wires and swapped the #5 coil with the #4 coil pack at the time of the plug and wire replacement. The CEL remained off until it got cold outside again then code p0305 came back, so I changed the #5 fuel injector and cleared the code... drove truck for 2 days before it got cold again and guess what? Yup your right code p0305 came back. Can someone give me a little help with what's next?

 

[Chuzz]

Are those the original wires? If so, perhaps it's time to change them. Resistance in the wire can change with colder weather.

 

[slefler]

Nope, I changed the wires when I changed plugs. I also changed #5 fuel injector. all parts were AC Delco.

 

[Chuzz]

Have you done a compression test to rule out a burned valve? You don't smell any rotten egg smell do you? If so, it could be cat con or 02 sensor related. Check the wiring on your 02 sensor and make sure it's connected tight and there's not a burned wire or maybe a wire that's been rubbed through and is grounding somewhere.

 

[slefler]

I haven't done the comp test yet, no rotten egg smell either. today I flushed the eng with one of those oil additives and had the oil changed. The dealer must have cleared the code for me as the CEL was off when I got the truck back. It is 35 deg today and light has not returned. so I think Ill drive it and see if it returns. I will also give the fuel inj wires a close inspection.

 

[Chuzz]

I'd do the same thing, just drive it and see what happens. The dealership clearing the code may have been all you needed.