2002 Chevy Avalanche Engine Misfire

LFGRECO

MEMBER
2002 CHEVROLET AVALANCHE
V8
2WD
AUTOMATIC
11,200 MILES

I had my avalanche check engine lite come on on the way to work, so on the way home I figured I would go by Auto Zone and check on the Engine lite, On the way home I felt a slight miss as I drove further It began to miss worse, when I got to auto zone. There code scanner said I had a Missfire, But wouldn't tell me which cylinder. So I changed plugs and NO change, So I checked the wires and the coils, They all check OK. Now the engine runs so bad, only 1, 3, 5, 7 cylinders are fireing correctly. #2, 4, 6, 8 Cylinders barely make a difference when I unplug the coils, It also smells like something electrical is burning under the hood. Do you think my computer is fryed? Please Help!

Monday, October 19th, 2009 AT 10:20 AM

4 Replies

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

HAve you had the computer rescanned? Have you checked the crank sensor? As far as the entire one side not firing correctly, are you sure you didn't mix up the wiring?

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Sunday, December 6th, 2009 AT 8:18 PM

LFGRECO

MEMBER
3 POSTS

The computer was not messed with but I did notice a rattle under the truck the day before that was comming from the cat converter but it stopped. Could the exhaust be plugging up on the right side?

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Monday, December 7th, 2009 AT 7:23 AM

LACELLER

MEMBER
1 POST

I had the same problem with my avalanche, and it turned out to be a front O2 sensor on the 2, 4, 6, 8 bank side. Mine was also burning oil. I took valve covers off and cleaned out pcv valves at same time as changing oxygen sensor. Runs like a clock now. Also had to change plugs again, 2, 4, 6, 8 were fouled in about 100km.

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+1

Thursday, January 28th, 2010 AT 8:32 PM

LFGRECO