Engine Running Ruff - Help
Thread Starter
Pro
Joined: Sep 2005
Posts: 700
Likes: 0
From: Casa Grande AZ
Engine Running Ruff - Help
My z06 has been running really ruff for awhile and the check engine light came on. Ran the code and it was an intermittent misfire. Mechanic changed the plugs and plug wires and check engine like went out but the exhaust just didn’t sound right. Check engine light came back on, but this time it a was flashing light. Put it back on the scope and ran the code which said that there was not enough air flow on the right bank. The air pump is working and the air flow is fine. The coils are working and the fuel injectors all check out and are working. The left exhaust is dark in color and the right is white. So it seems that the exhaust is restricted on the left side in some way maybe the catalytic converter is blocked? What do you think????? Guess I'll run this in the Tech section as well.
Racer
Joined: Dec 2007
Posts: 354
Likes: 4
From: Grand Ledge Michigan
Get one of those laser thermometers from Harbor Freight, Sears, ect. I think I paid $40 for mine at Harbor Freight. Drive it around the block a few times and measure the temps of manifolds at 8 exhaust ports, pipes, and exhaust. Compare temps before and after Cats, each side, ect. Might be a good place to start to look for blockage.
Instructor
Joined: Apr 2008
Posts: 147
Likes: 50
Personally, I would say that it might have something to do with your catalytic converter. If it is blocked, then you would have a hard time getting up to speed. It will run fine for about 20 seconds, and then after that, the back pressure would build up inside the engine.
Good luck finding out what's wrong.... Have you run a diagnostic scan yet, since the new check engine light came on?
Good luck finding out what's wrong.... Have you run a diagnostic scan yet, since the new check engine light came on?
Advanced
Joined: Dec 2006
Posts: 75
Likes: 1
From: Rhode Island
Save your money on the temp tester then spend it on a full diagnostic scan. A temp test at the maifolds will be inconclusive at best unless of course you have a totrally dead hole. Given that your car has OBDII diagnostics you will find a more direct path to your problem using the data stream the car was built with. The technician perfoming the test will be able to determine if either "cat" is functioning or not and if it's malfunction is a by product of your problem or the root cause of it. Bottom line is that your car has a very sophisticated engine management system with diagnostic and bi-directional capabilities. Use these as the first order of diagnostics rather than the last. Lest us know what you find.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
It sure sounds like a restricted exhaust. Have you tried putting your hands over the rear exhaust outlets, comparing sides? Have you rechecked the spark plug wires to insure one or more didn't come back off a little? On the plugs, did he change the spark gap from the original setting... which plugs, what gap was used?
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