Hey guys, I've been having a problem with my 1.6 Focus, 125k km. Along with a very small misfire on cylinder 1 (P0301) which rarely shows up as a check engine light but does show up when reading the codes as PENDING, there's a problem when the car is coming to a stop (at an intersection for example) and I press the clutch, the revs fall and usually the engine manages to keep itself alive, but sometimes the engine just stalls.

I have no idea why this happens, spark plugs and HT Leads are relatively new, coil pack and air filter are brand new. Both O2 sensors are working perfectly. I've swapped the spark plugs around and the fuel injectors too, misfire stays on the first cylinder.

One thing I have noticed is that when I'm stationary and i keep the revs at around 1500, I can feel the misfire. I've checked STFT and LTFT values and I can sometimes see the engine running too rich. Sometimes the STFT goes to around -20 and while driving and when checking the voltage, I can see it going to around 9v for a millisecond then jumping back to a constant 14v. Checked with 2 different batteries.

Anyone that had the same problem can bring some light to my problem, it's driving me crazy. Thanks!

You need to do a Compression Test and see what the results are.

1 hour ago, Tizer said:

You need to do a Compression Test and see what the results are.

I tried doing one today but it seemed like my compression test kit wasn't fitting into the spark plug thread. Saw that you need a special adapter for these engines or something like that but can't seem to find it anywhere.