Bad Ignition Coils?
#11
Well I have a 2.8L A4, but I didn't want to thread-jack. I'll go to auto zone again and have them pulled. My friend has a reader and it said Misfire detected, Misfire detected cylinder 4 I believe. I'll go this afternoon and have it checked out.
#12
Ok finally ran the codes
P0300 - Cylinder Misfire detected random cylinders
P0303 - Misfire Detected - Cylinder 3
P0304 - Misfire Detected - Cylinder 4
P0411 - Secondary injection system fault
P0171 - Fuel Trim bank one condition (After pulling the code off a list on the internet it said: System too Lean (Bank 1))
also, all the car places were very weird about it being a misfire, when I said "I'm pretty sure it's the ignition coils" just about all 3 places I called said they had to run a diagnostic to be sure BUT they didn't have a diagnostic computer for Audi's. So I took it to Autozone for these codes. A quick reply would be awesome as Autozone said they could order some in, but all the car places want to charge me $70 for a diag. first.
P0300 - Cylinder Misfire detected random cylinders
P0303 - Misfire Detected - Cylinder 3
P0304 - Misfire Detected - Cylinder 4
P0411 - Secondary injection system fault
P0171 - Fuel Trim bank one condition (After pulling the code off a list on the internet it said: System too Lean (Bank 1))
also, all the car places were very weird about it being a misfire, when I said "I'm pretty sure it's the ignition coils" just about all 3 places I called said they had to run a diagnostic to be sure BUT they didn't have a diagnostic computer for Audi's. So I took it to Autozone for these codes. A quick reply would be awesome as Autozone said they could order some in, but all the car places want to charge me $70 for a diag. first.
Last edited by Lyle_Hatt; 11-24-2009 at 12:29 PM. Reason: more info
#13
Assuming it's a 1.8, take the coil packs off the cyl 3 and 4 and switch them to 1 and 2, drive the car a little bit, and rescan the codes. If the misfire follows, it's the coil packs, if it doesn't follow, then it's not your coil packs...
#15
not really. a compression test would diagnose headgasket or valve damage. its probably a MAF sensor error due to multiple random misfires and the lean code, or possibly primary O2 sensor. do what brad suggested and swap coils. if the misfires dont follow to the exact cylinder, the coils arent your problem.
#17
Your MAF (Mass Air Flow) sensor measures the amount of air entering the system. If it's not reading correctly, (to low for example) then the car is sucking in more air than it thinks and doesn't adjust the fuel level correctly, causing the O2 (oxygen) sensor before the Catylitic Converter to read that you are running lean (not enough fuel).
The MAF is fairly easy to clean, but if that was the problem, more likely than not you would have misfires on all cylinders, not just two of them. The coil packs are easy to swap around and will tell you if that's the problem. If not, then check your plugs, and clean your MAF.
The MAF is fairly easy to clean, but if that was the problem, more likely than not you would have misfires on all cylinders, not just two of them. The coil packs are easy to swap around and will tell you if that's the problem. If not, then check your plugs, and clean your MAF.
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