KRYPTONITE

I have a 03 Jeep Grand Cherokee with a 4.0L it has 134K miles

Last week it started to misfire and the Check Engine light was flashing and stayed on and these were the codes a PO300,PO305,PO306. Did a comp. test. (185-195 on each cycl.) I changed the Spark Plugs with a NGK(nothing special) and the Coil Packs (rail style) the check engine light went off after that and haven't had a problem for about 5 days of driving, This morning the Engine light came back on and it was misfiring badly, same codes PO300,PO305,PO306... Should I change the #5 and #6 Injectors?? or is there something else???

Anyone else have these issues!! Any help would be greatly Appreciated

Bustedback

It could be something as simple as a bad electrical connection at the injector, or low fuel pressure. You could swap the position of the injectors and see if the miss follows.

KRYPTONITE

Yea I Might swap them and see if it stays with the number cycl. or that injector.
Thanks


Does this year Jeep carry a external Fuel Filter??

dave1123

I don't believe so.

KRYPTONITE

Ok so I haven't had a chance to switch Injectors, and it hasn't given me any issues since, except this morning on my way to work, But as it was misfiring (65mph) I put it in neutral and shut it off and cut it right back on and stuck it in Drive, Misfire went away and ran fine!!!! this has we alittle lost now, any new input?

KRYPTONITE

Anyone know why it would do this^^^^

Bustedback

Possible PCM.

KRYPTONITE

That's what I was thinking....sounds like a lot of Money

Bustedback

Not as much as you think ...if you can find one.

KRYPTONITE

wheres the best place to look sir.?

Bustedback

Napa, but it will need to be flashed by the dealer.

KRYPTONITE

Awesome thanks man!!