LT1-LT4 Modifications 1993-97 Gen II Small Block V8

94 Z28 rough idle and missing when warm

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Old 03-06-2013 | 09:03 AM
  #21  
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From: Jackstandican
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Unplug the O2 sensors and run the car to operating temp. See what happens. If it runs fine then most likely your O2's are bad.
Old 03-06-2013 | 08:50 PM
  #22  
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Well..I'm not having the problem nearly as bad anymore. Not sure what it was. Replaced the cheapest part first (fuel filter) and ran some seafoam though it. It was actually driveable after that. But I'm still having a slight idle problem. I also realized today that my cat is definatly bad. So I'm going to put some long tubes on it. Y-pipe. Go cat-less. Then put a new opti on it. Plugs and wires. And see whats going on with the water pump while I'm in there. Like i said above. Is it possible for a bad cat to cause the rough idle?
Old 03-06-2013 | 10:40 PM
  #23  
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Just my two cents on my experience. I had the same exact problem. I changed the opti, icm, plugs and wires, and 02 sensors with no help. For my car it wound up being the ecm.
Old 06-03-2013 | 12:30 AM
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I took my ICM to autozone and they said it was fine. Only to find out later that it was bad. Its cheap I would just replace it to be safe. 94 Camaro lt1



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