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Discussion Starter #1 (Edited)
I got an 02 Envoy a few months ago. 140k miles on it. as usual right after there awesome 1 month warranty (sarcasm) expires problems arise. 3 coils replaced, i replaced all the spark plugs with cheap autolites. (im broke as a joke) the engine knocks shortly after i got it. It all went down hill recently. It was time for an oil change. I changed the oil and filter. Now its idling rough. I keep checking this site, so then i took off the throttle body and cleaned it up. Idle is worse. I had the battery unplugged to reset, then drove it for a while. still is **** idle. Seems to idle better cold. When warmed up it bogs like it will stall. It hasent yet though. RPM's jumping up and down consistently. between 600 to maybe 900. I checked all the coils and they work. even if the RPM's dont jump up and down the engine still bogs. everything else is fine while driving. It is only if i stop.

so far i have done:

Oil change
Oil filter replacement
Coil check twice, had to replace 3
Throttle body clean, from the instruction on trailvoy forums
All new spark plugs (cheap autolites)

Is everything in the dash supposed to reset when i unplug battery? it still tells me my trip miles, avg. gas mpg and all that.

check engine light came on today but autozone gave me codes i dont think exist for this vehicle. p0400 and p0325. p0400 says EGR valve, from what i see this vehicle doesnt even have? I am so lost and cant send to a mechanic due to being laid off with low cash and my father is mentally ill about to lose his job too. everything is on me. this car has me stumped.

Desperate for help
 

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2005 gmc envoy_slt
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If the truck had amisfire for a while it is very possible that the catalytic converter is severely damaged and clogged. The excess exhaust backpressure couod cause an egr code and lack of power/bogging on acceleration. I would start by testing tge cat. Have an exhaust shop do a backpressure test. If you are in a ham you can also remove the upstream o2 sensor prior to the cat and start the truck to see if it runs and drives better. If the cat is in fact clogged. Running the truck without the 02 sensor will alleviate enough back pressure to make a considerable difference.
 
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