ChristopherI

Hi everyone, new to the forum. I did however spend several days combing through all the releated issues before posting my own. Any input will be most welcome.

-Primary symtom- Rough idle when stopped in gear or reversing (hiccups/hesitations/sputtering)

2004 Jeep Cherokee 4.0L - PO122, PO123, PO300, PO301, PO305, & intermitant PO441.

Evap code was the first one to pop up, good gas cap, replaced a bunch of vacuum hoses now its been off for several days.

TPS HI-LO Voltage codes were next followed by Misfire in cylinder 1. yesterday merging onto the interstate started shaking violently and MIL started flashing triggering P0300 multiple misfires and cylinder 5 misfire.

The jeeps idle hesitates/spudders/misses when in drive or reverse at a stop or when brakes applied but operates normally when in netural or park or while driving unless under stress (heavy acceleration - passing, merging onto the interstate, etc.). This has been happening since i bought the jeep in Jan12, prior to ever having any MIL codes. (research online points to bad rear 02 sensor despite the 02 not throwing a code.) will unplug it when the rain drys up and see if it resolves the rough idle.

keep in mind the rough idle was present hundreds of miles & weeks before the TPS codes were thrown. So I'm thinking the P0122 and 123 were results of the actual issue, rather than resulting in the issue.

Before I start throwing parts at it I would love some input.

Firestorm500

You posted in the regular XJ forum, but I would start looking at coil(s).

ChristopherI

yeah my bad... I reposted in the oem tech forum... I think.

Turbo X_J

https://www.cherokeeforum.com/f5/

KD4315

Start simple. How are your spark plugs? When was the last time they were changed? I'm not that familiar with WJ's but I assume you have coil packs and not a Dist Cap and wires. When the CEL light starts flashing that means it's going to go into limp mode and I suggest not driving it until you can figure this out. Evap code was most likely due to not putting the gas cap on correctly after your last fill up.

ChristopherI

Gonna pull the plugs first thing in the morn. Got a buddy bringing over a multimeter to test the injectors & tps sensor. BTW just found this kick*** site that walks you through testing sensors, injectors, etc using a multimeter. Gonna pull out the rear O2 sensor and blast the carbon buildup off of it, spoke with an ASE Tech earlier who had similar issues with his Durango 02 being defective but not throwing any codes. Maybe I'll get lucky. yeah...


http://troubleshootmyvehicle.com/ind...articles_1.php


Let ya'll know how things go tomorrow.