Engine Performance problem
1996 Jeep Grand Cherokee V8 Four Wheel Drive Automatic 67000 miles
The jeep throws a P0351 code almost imediately after codes have been cleared. The idle is slightly rough and the jeep has no get up and go. I have an otc scan tool. It won't read any data except in global obdii mode and when I try to clear codes it says there is no comunication yet it will supply live data. I did notice the short term fuel trim bank 1 sensor 2 is stuck at %99.2 and the last time I hooked it up at idle the tps read 13% but that wasn't hapening in the past. Also if I leave the battery out for a period of time the jeep will not stay running w/o giving it some throttle. This lasts about 5-10 min and then it runs fine (hits closed loop perhaps?). Also important to note it does have msd ignition installed but bypassed it has the same problem. Some history. The jeep hasn't moved in a year but has this problem before that. The problem started within a month or 2 before or after my cat converter broke apart. It has been replaced. Has new cat, spark plugs, coil, crank sensor, iacv, rear o2. So far it seams the pcm must be the cause. Tested ohms and fount no short to ground in the coil circuit. Any other likely possibilities?
Monday, October 11th, 2010 AT 8:02 PM