1996 jeep Cherokee 4x4. runs great. Idles great. Great power. Drives great . Then one day it will just lose power at the pedal , feels like its going to die but does not. I have to slowly give it fuel to slowly build up to speed again. Feels like it wants to cut out. Sitting still revs up fine. When problem happens it will not rev while driving. You might go 2.3 months without this problem but it comes back when it wants to. Checked codes and they are 172,171.

 

Both of those codes point to the O2 sensor.

 

I was going to suggest O2 sensor as well. I had a similar issue in my 92 and a new O2 sensor fixed it

 

Both 02 sensors have been replaced. Also new fuel filter . I did this when I first experienced the problem.

 

Sounds like the throttle position sensor to me. It needs proper info from it to keep the mixture correct. When it doesn't happen, you get a lean condition that will cause misfires, and also stalling

 

Did you use an NTK O2 sensor? Jeeps can be finicky with O2 sensors that aren’t OEM

 

whack the catalytic converter and listen for junk rattling around inside.

 

I am going to change that because its a easy change. But would that also cause a rich code at the same time ? The jeep does not stall . It will die down to idle where as long as your not moving it will rev no problem. This also is not a continuous problem . The jeep does it when it feels like it. I have searched all over the net and cannot find anyone having this same issue. My next step just to know , is to check the fuel pressure at the rail. Pump has been changed , filter , and I have run thinner through the system. It will be a new jeep when I am through replacing parts. hahahahaa Thanks for the help.

1996 jeep sport red
4.0
240k+
new brakes, rear shackles, fuel pump ,filter, stabilizer shock, new shocks front and rear, new links , new plugs and wires , new air filter , pvc .
no fluid leaks, no smoke . Starts up quickly every time. idles perfect.
I run a high mileage oil with restore additive.

 

Sounds like your transmission shift solenoids (solenoids 1 and 2) are switching to the OFF state and leaving you in OD (4th gear). If this happens at a speed lower than about 40mph, you'll feel like it is bogging, but it won't completely die. It will seem to get better as your get over 40mph (which is about the minimum speed at which OD/4th should come in).

Have you tried manually down shifting when this symptom occurs? Depending on what is failing, this may not help, but it is worth trying/testing.

If your 96 has an OBD2 port, you may want to get a cheap scanner so that you can see what your computer is reporting for throttle position and speed. It could be that the solenoids are fine, but that the computer is getting bad sensor data. These scanners can be had for about $25 these days. Incidentally, it will also show you what your fuel trims are doing which will help to identify O2 sensor issues.

 

Emissions issues like an Oxygen sensor or clogged catalytic converter can mess with the fuel trim, yes.

 

I had the EXACT problem with my 96', I replaced the O2 sensors just for the heck of it a couple months prior with Denso O2 sensors and once these issues popped up, I put in OEM NTK sensors from RockAuto and it fixed the problem 100%

 

I had the problem before I changed the old sensors out. The problem does not cause the check engine light to come on. I may go out and drive the jeep and it may run for 2 months and be no problem then it starts. After looking at the advice I am going to 1. change throttle position sensor.2. check my rail pressure.3. change my crank position sensor. Run a good catalytic cleaner through. Wait for the problem to reappear or not. Thanks.

 

Its not bogging. No power at all at the pedal. It does have a OBD2 port and I have a scanner. I will use the scanner info on the website they have to look into it deeper.thanks.