new KJ owner here.
last Tuesday we bought a KJ for my daughters first car from a private seller.
we found a clean 2004 Limited in good condition with 160,000mi. at a reasonable price.
the vehicle looked to be well taken care of (as did the sellers other vehicles and his house and yard)
we test drove the car for about 30 min in mixed conditions and everything seemed to check out.
after we got it home and my daughter drove it around to some friends house she came home and said that the check engine light had come on as she was coming up our street.
I did the key on-off thing and found one error code P0302 misfire on cyl 2.
I replaced all spark plugs (with the recommended NGK units)
and also replaced the coil on cyl 2.
when I took it apart I noticed that the coil that was on cyl 2 was much cleaner than the rest of them and the plug that was in cyl 2 was an autolite and the rest were NGK.
so obviously someone was trying to correct this problem in the recent past.
after replacing all the plugs and the coil I cleared the error with my OBDll reader.
everything was fine for a few hours of starting stopping and driving...
then the CEL came back on. I hooked the scanner back up and found the same error P0302...actually my scanner reported two errors but they were both P0302. but the second P0302 had a (pd) after it...
to be clear, as I scanned the errors the first error said "P0302 misfire cyl 2" and the second error said "P0302(pd) misfire cyl 2" I am not sure what the (pd) means and I couldn't find it in the book that came with my scan tool.
the engine seems to run fine with none of the symptoms of a misfire or the dreaded valve problem I have recently found out about.
the engine idles smooth, no pinging or knocking, no hesitation, no low idle, no trying to stall when stopping, seems to be fine except for the CEL.
soon I will have to have state emissions testing done and it will not pass with the CEL on.
I am guessing my next step is to replace the injector on cyl 2. and do a compression check on that cyl.....god I hope it is not a valve problem we simply don't have the cash reserve for that!!!!
anyone have any insight as to what this can be and how to fix it.
I have read that a bad O2 sensor could cause this but I can't figure how it would be cylinder specific. but I don't know as much about these 3.7L as I would like...
thanks for the advice.