I have a 2011 audi a5 with a 2.0 tfsi engine with 97,000 miles and its a manual I have a misfire in cylinder 3 I replaced the spark plugs and coil packs and switch the coil packs with other ones on the engine and still get a misfire and I replaced the intake manifold it was really causing all 4 cylinders to misfire and that took care of it but then I still got a misfire in cylinder what you think it would be
so only cylinder 3 is misfiring, even though it has a new injector, new spark plug and coil, and the compression is good?
- One of those parts is defective, or
- Computer
Yes everything read good but still haven't figured it out and I am lost what to check next
I even did a compression test on it too and replaced all 4 fuel injectors
What did the compression test show? Do you really want to still keep throwing $$$ at it?
It read 130 for all 4 cylinders and I have a loan on the car I owe 16,000 on the car yet so I really have no choice to keep throwing money at it
Damn! Have you checked all the wiring to the coil & injector to make sure it’s not the culprit? It could well be the main computer as Joe mentioned, if none of the other things fix it.
https://www.engine-codes.com/p0303_audi.html
And a while back I did have someone reset the ecu so it can relearn but still didn't fix it
From our FAQ misfire page:
Diagnosing
Here are the easiest tests you can do to verify some of the possible causes
- Spark test
Pull out one spark plug at a time. If a spark plug is wet with fuel, it usually indicates a lack of ignition.(but could also be fuel flooding) Disconnect EFI fuse, lay the spark plug on the engine block so it's grounded (or use inexpensive ground clip) and briefly crank the engine. Make sure the plug produces a good hot spark. - Fuel test
Attach a pressure gauge to the fuel port, turn the key and wait. Make sure it maintains pressure. - Compression test
Disconnect fuel. Remove spark plugs one at a time, and insert pressure gauge. Disconnect EFI fuse. Crank the engine. Piston should generate at least 100 PSI - Isolate components
If you have some cylinders that aren't misfiring, then try putting components from those cylinders into the misfiring ones (spark plugs, coils, injectors etc.) - Catalytic converter
Gently bump your catalytic converters. If they rattle or you suspect they are plugged up, remove the upstream oxygen sensor and see if engine runs better. - Vacuum leak
Spray starting fluid around the air filter housing, intake manifold and the various hoses. If the engine speeds up or gets louder then you have a vacuum leak. Sometimes you can hear the air hiss from the leak point. - Engine Banks
Some engines, such as the 'V' shaped engine (V6, V8 etc.) have cylinders divided into banks. The image below shows a V8 engine. If you are getting misfires on only one bank, for example cylinders 1,3,5 or 7 , then that usually indicates an intake or head gasket failure in one bank. Cylinder numbering starts at the front of the engine on the driver's side.
