jonwalden68

I have a 98 cherokee 4x4 completely stock has 122k on it. I bought it a month ago and been notice sometimes after startup I will pull out and about 100 ft or so it has a sputter and loss of power some backfire through intake sounding if I let off gas it will resume normal driving and have no issues and it doesn't do after every startup just every now and then. What could cause this previous owner installed new muffler and cat and there is no codes or stored codes. Only other thing I notice is when driving at higher speeds and let off gas the Rpms will kind of move up and down once it hits bottom like its not steady. But I want to fix it because I love the cherokee and want it too last me for a while any help me appreciated

Badmunky

I have the same problem with my 98 Grand Cherokee 4.0.

I did a tune up and that did not fix it.

Plugs.
Cap.
Rotor.
Wires.

So Next on the list is to replace the front O2 sensor. From every thing I have read thats the next most likely cause.

Muaddib420

When was the last tune up? If your xj is new to you I would assume the PO never did it. Start with new plugs (champion coppers gapped to 0.035), cap, rotor and wires and go from there. Could be just a bad plug, which doesn't always trip a check code.

jonwalden68

I was told it had tune up but I'm gonna look at this weekend now today I noticed the oil pressure gauge was dropping lower then normal not all the way down bout a quarter to end

98_XJ Sport

If it sits for longer than a few hours does it have difficulty starting or it has extended crank time?

DieselD

I have the exact same problem...

However, I have 3 codes, one for over voltage on engine coolant temp sensor, two for the downstream o2. I'm replacing the o2 sensors soon, I expect them to be the culprit.

Lowrange2

My wife's Jeep did this EXACT same thing.

I replaced the upstream O2 Sensor and it hasn't done it since.

Replace the oxygen sensors!

DieselD

That's reassuring to hear. Thanks. Like the new avatar btw.

jonwalden68

No it starts perfect everytime I think it's the map sensor or oxygen sensor I'm gonna replace both oxygen and go from there and will do a tune up but what plugs do you recommend I heard some work better on jeeps them others?

Also what cause the oil pressure to drop when coming up to red light drops to about 1/4 on the gauge then start driving and goes back up to a little below half is that normal? And after it sits and cranks up the pressure is normal thought sensor might be goin bad

jonwalden68

Did you use factory ones or the Bosch ones from advanced auto? Also how much do factory ones run

DieselD

I haven't replaced mine yet. That was Lowrange. Lol.

When I do I'm using NTK ones, what the factory used. Probably order from rockauto.

Lowrange2

Rock Auto has fair prices. Do yourself a favor and swap the O2 sensor first.

jonwalden68

I love rock auto besides there shipping is expensive to Georgia lol but ill try the factory ones

jonwalden68

Haven't had a chance to do the o2 sensor yet but on a good not I did get my lift kit ordered 3" rough country with 1" spacer in front and 15" d window wheels with 31x10.50 kenda mud tires does anyone know the center width on the rough country wheels for center caps? I didn't want to go to high

jonwalden68

Well got o2 sensor ordered and going in tomorrow also gonna have everything looked over by mechanic anything else yal think it could possibly be