Need help! After I replace exhaust manifold, oxgyen sensors, timing belt/water pump, new plugs/wires/cap/rotor, the code showed up as P1399 and P0302 (#2 cylinder misfire) Compression 180 good, motor runs like 3 cylinders, put old plug back in same thing. At first I thought the #2 injector is bad because when I pulled the connector off, same effect. But I do the experiment, swap the injector around and I would expect that #1 will be misfiring but it didn't and #2 is missing. I checked the wires from injectors to PCM. All good with 1.1 ohms each. There is voltage on yellow/black terminals but I didn't check the brown, red, blue and yellow wires (managed by PCM) for fearing of frying the computer. It also shows P1399 too. Any suggestion and they are greatly appricated.

 

welcome to the forum, did you do the swap on the #2 wire, recheck the spark plug for grounding or proper sparking.

 

It has history of misfiring in the past. Firing order is correct and either the old or new spark plug doesn't solve the problem. Valve clearance was tad too loose and I set them to the .007 for intake and .009 for exhaust. Compression on #2 is 180. ALLDATAdiy pinpoint to PCM and possible the crankshaft sensor on the crankshaft pulley side.

 

you're doing some good trouble shooting. I don't seem to be finding much more to fix the misfiring cylinder.