Ryan Fairchild

I had a thread a while back about a misfire problem i was having in my 2000 cherokee 4.0. The problem seemed to have gone away after installing a new coil pack and spark plugs, but today it started up again with it running terribly through all engine speeds. The check engine light started flashing, and I decided it was time to pull it back in the garage.

Now having the ignition almost all new, I figured it was a fuel problem and my OBDII scanner confirmed - PO171 Bank one too lean, PO174 Bank 2 too lean, PO306 misfire cylinder 6 and PO456 small evap leak. I recently did a little work to my fuel rail, one O ring on the injectors was starting to spit fuel so I replaced all 12 and it ran fine for a day, then this. Anything to try troubleshooting would be greatly appreciated!