Expert: Robert Summers - 1/15/2008

Question
QUESTION: My 03 Tahoe would idle rough and has a hesitation. Engine light came on and I had it coded it said misfire on 2 cylinders changed wires and plugs drove for a few days light came on again it coded lean on bank 1&2 had fuel filter put on and still did the same thing.  Had fuel pump replaced and I'm still having the same problem.  Do you know what else should be done.  Car idles rough and has a hesitation sounds like its going to stall.

ANSWER: Hi Terry... have you tried cleaning the IAC.... use a good air intake cleaner, do not use an abrasive on the pintle...also check for dirty inj....hope this helps

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QUESTION: Could a cracked intake gasket cause this problem?  Have heard this could be a problem with GM?

Answer
Hi Terry....yes it could....quick test would be to take a propane torch, do not light it, turn it on, start engine and run the torch around the gasket... if engine picks up rpm at any spot while doing that i would suspect the gasket is sucking air...hope this helps