Expert: Robert Summers - 4/25/2008

Question
Hi Robert,  Thanks for your help.  I have a 2001 Yukon 4.8 2wdrive that we bought new.  I've not had any serious problems.  Occasionally it will die at idle.  When that happens I take off the air intake and clean inside with carb spray and a rag.  That seems to fix it.  I did new plugs at 100,000.  I did not change the wires.  I've got 3 trouble codes right now P0305  P0332  P0446.
Only P0446 is a pending code.

The P0305 has happened off and on for the last year.  I haven't been able to figure out what is causing it. This is the 1st time I've seen the other 2 codes.  When accelerating I can hear a knock that sounds like spark knock.  

Any suggestions on where to start will be appreciated.
Rick

Answer
Hi Rick. i would have to do some investagating but i would suspect that a complete tune up would help. spark knock can be caused by a delay in the spark due to restance in the wires. also check the knock sensor it's self...if you cleaned air intake try clearing codes and run truck see what codes if any come back... then message me with codes... hope this helps