Just finished up a rear main seal replacement (pulled tranny/transfer case). Before starting up, i pulled coil wire and check compression on all 4 cylinders. coil wire arked out while checking #3 (4-5 cranks). Compression checked out OK and finally fired up. Check engine light is now on constantly. checked codes and pulled a 13 - Knock Control CPU. Engine seems to run fine but I can't figure out what's wrong or if the coil wire arking out has anything to do with the code 13. Any Help would be awesome.

 

Has the wire came off the knock sensor? Located above starter, about halfway up the motor and about middleways. Possibly a yellow connector. Not to be confused with the oil pressure sending unit.

 

I checked the knock sensor and the wire appeared to be fine. I need to check wire and sensor further. The wire has been replaced once by someone other than me over 12 years ago.