misfire and flashing check engine light? 4.0 inline 6 engine
Asked by Thorin Feb 08, 2017 at 12:58 PM about the 2003 Jeep Grand Cherokee Laredo 4WD
Question type: Maintenance & Repair
Ive been getting a misfire when the engine temps gets to 210F, it will only do
this if it is idling, ounce i get the temp back down the misfire will go away, I am
thinking it is a catalytic converter based on what i have read online, It had 3
cats, 2 in the manifold and one down stream. Is the cats or something else, i
cant figure it out and i dont want to take it to shop.
6 Answers
That's what the flashing check engine light means. Random misfire. Check for codes to see where to go from here, if u keep driving it with misfires, it will plug up the catalytic. Ur misfires could be due to dirty throttle body, low fuel pressure, bad injectors among other things
the misfires didnt start happening until i started to put winter mix gas into, if i cat is bad which one is it? Correct me if i wrong but since it does have 3 cats does that mean it has the California emissions standards, i live in in ohio so im not really for sure.
So is it possible that I'm am losing spark and the unburned fuel is going into the cats causing the flashing light? It's acts like it misfiring but if I hold the rpms up for a little bit it clears up and and everything is fine agian
Something like that. Ur feeding fuel or lack of, that is not being properly burned and C02 sensors detects the inefficiency and turns check engine light on
Mine was the same problem I just found my num # 7 injector at the back pissing fuel out and it caused sunburnt fuel thru exaust and black suot on the ground at end of tail pipe
I've had my 2003 Gr. Cherokee for about 3 years now. Most of the time, the check engine light was on due to O2 sensors needing replaced and now more recently, the EVAPS having a small leak somewhere. But tonight, coming home with a carful of friends from a nice dinner, the poltergeist in my car starting acting out again. Never before did I see the yellow check engine light flash like that and then the car was idling badly and bucking a bit. I pulled over, popped the hood and it seemed to be running hot even though I only drove about 3 miles. My fluids all checked out at normal levels, and the car temp never showed the vehicle overheating. But starting it up again, the diagnostics read: Milage 12.5mpg. This is really bad, as it normally gets 20 mpg. Again it was running rough until I floored the engine up to around 3500 - 3800 rpms for a few seconds. I let off the throttle and - tada - it resumed idling just fine. WEIRD!
