2002 Chevrolet Tahoe Misfire Codes

2002 CHEVROLET TAHOE
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LEEP4321
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  • 1 POST
We have a 2002 Tahoe LS with about 96000 miles.
For about 2wks now the check engine soon light has gone on and off, blinking and constant. The car runs well. We have taken it in 2 times so far - $110 later and it is still on. Both times the code is P0300 4 and 5 misfire. So far they have cked using injector drop test and all dropped to 8PSI (in spec). Performed the crankshaft variation re-learn, cleared code and road tested. I am not sure what all this means as I am reading from the invoice. They stated if it came back on- which it is, they would suspect the intake gaskets and that would end up costing $400-800.
Any suggestions on what to do next?
Jan 16, 2007 at 11:47 AM
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MATHIASO
  • ✓Experienced Mechanic
  • 1,209 POSTS
it's look like a guessing game.
ask them to do a compression test in all the cylinders, to be sure that there is leak probably cylinder 4 and 5.
it's may be a simple spark plug gasket or seat, broken intake valve,exhaust valve, piston rings,or head gasket.
Jan 16, 2007 at 4:19 PM
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SERVICE WRITER
  • ✓Experienced Mechanic
  • 9,123 POSTS
If this is a 5.3, check the fuel pressure regulator for a very fine leak.
Jan 16, 2007 at 4:55 PM
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Suggested Repair

Perform a compression test on all cylinders, especially 4 and 5, to check for leakage from a spark plug seat, valves, piston rings, or head gasket. If the engine is a 5.3, also check the fuel pressure regulator for a very fine leak.

Conversation Summary

A 2002 Chevrolet Tahoe with about 96,000 miles has an intermittent check engine light and P0300 misfire codes for cylinders 4 and 5, though it still runs well. Injector drop testing and a crankshaft variation relearn did not resolve it, and the shop suspects intake gaskets. Experts recommend a compression test on all cylinders and, if it is a 5.3, checking the fuel pressure regulator for a fine leak.

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