Good morning, hoping someone can help me troubleshoot a bank 1 misfire im having.
Car: 99 Cobra, ProCharged, aftermarket fuel pump, stage 3 comp cams, BA2600 MAF
Issue: misfire on entire bank 1 (Cyl 1-4). Had a P0171 code a few months earlier but cleared it and it never came back. Can hear an audible misfire from the exhaust at idle.
What I have tried:
After letting the car run to get up to temp. The driver side (bank 2) high flow cat gets up to 400 Fahrenheit. Bank 1 cat is only 150 degrees. (Probably normal since bank 1 is not firing correctly).
Seems the car is running very lean, showing high fuel trims on both Bank 1 and Bank 2. When I rev the engine and hold it at 2k RPMs the fuel trims seem to even out pretty good.
At a loss here on what i can do next before sending it to a shop...
My next steps:
Test fuel pressure
Clean MAF (had to get a T20 security bit to remove)
Replace EGR
Car: 99 Cobra, ProCharged, aftermarket fuel pump, stage 3 comp cams, BA2600 MAF
Issue: misfire on entire bank 1 (Cyl 1-4). Had a P0171 code a few months earlier but cleared it and it never came back. Can hear an audible misfire from the exhaust at idle.
What I have tried:
- Replaced all 8 spark plugs
- Coils were replaced in Jan 2024. Tested coils on bank 1 by grounding spark plug to engine and turning over. All 4 cylinders are sparking.
- Fuel injectors were professionally cleaned, no issues
- Verified injector voltage and ground on all 8 connectors with power probe. Getting 12v, ground is present.
- Performed smoke test to check for vacuum / intake leaks. No visible leaks found.
- Verified factory grounds are secure.
- Replaced both upstream O2 sensors.
After letting the car run to get up to temp. The driver side (bank 2) high flow cat gets up to 400 Fahrenheit. Bank 1 cat is only 150 degrees. (Probably normal since bank 1 is not firing correctly).
Seems the car is running very lean, showing high fuel trims on both Bank 1 and Bank 2. When I rev the engine and hold it at 2k RPMs the fuel trims seem to even out pretty good.
At a loss here on what i can do next before sending it to a shop...
My next steps:
Test fuel pressure
Clean MAF (had to get a T20 security bit to remove)
Replace EGR