NTXisf3

Hi guys, have been having issues with these codes for a year now. Had some top end work done to the motor a few years ago. Will have to dive into my records for specifics of what was done.

Essentially the car is running poorly, engine light coming on after clearing of the codes and even going into limp mode some times.

I understand the code is a misfire in cylinder 4, I have changed plugs, coil packs. Had someone look into compression and they came back with it seemed fine.

I am looking to see if anyone has any recommendations of what it could be and how I can get her running clean again. She is a well used car with 320,000 km on her but meticulously maintained and single owner.

Any insights would be appreciated.

Thanks.