HELP: Rough idle - M271
08-14-2006, 03:44 PM
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HELP: Rough idle - M271
2003 early build C230 Sports Coupe
65K miles
Put in 94 octane for fun (it was cheap) and installed the Renntech pulley on my car. 1 week later, CEL and rough idle.
Codes are:
P0135 (O2 sensor malfunction)
P0301-303 (misfire on all cylinders)
Also mentioned other codes, yet not sure what they mean:
201B-016, 032, 064, 128
Dealer says the car is running lean, yet not sure what steps to take next without guessing. I'd like to have a plan of attack.
So far I have read that it might be:
1. coilpacks (highly unlikely)
2. spark plugs (due to be changed)
3. MAF (again, about time most fail)
4. injectors/fuel filter
5. wires (on the M112 it was common, not sure about the M271)
6. vacuum leak
I was wondering what I can do to test each of these rather than let the dealer spend a few hours and charge me a lot.
65K miles
Put in 94 octane for fun (it was cheap) and installed the Renntech pulley on my car. 1 week later, CEL and rough idle.
Codes are:
P0135 (O2 sensor malfunction)
P0301-303 (misfire on all cylinders)
Also mentioned other codes, yet not sure what they mean:
201B-016, 032, 064, 128
Dealer says the car is running lean, yet not sure what steps to take next without guessing. I'd like to have a plan of attack.
So far I have read that it might be:
1. coilpacks (highly unlikely)
2. spark plugs (due to be changed)
3. MAF (again, about time most fail)
4. injectors/fuel filter
5. wires (on the M112 it was common, not sure about the M271)
6. vacuum leak
I was wondering what I can do to test each of these rather than let the dealer spend a few hours and charge me a lot.
