Hey guys, my 1999 cherokee sport is having this loud clunking up front, lurching forward issue and then getting a CEL when hitting anything above 60MPH+ on the highway. If I pull over, let it sit, the CEL goes away and then the code is no longer stored. I just replaced the cap, rotor, spark plugs, wires, cam sensor and still having the issue. I'm not sure what to check first.

 

Do you have a code reader?

I would have one on hand so when the issue occurs you can read it immediately after it happens. Also, just because the light goes out, that doesn't necessarily mean there isn't a code stored.
I have a Bluetooth obd2 dongle and the Torque app on my phone. The dongle is like $15 on Amazon and the app is like $6. Works great, and inexpensive. Comes in handy for things like this.

 

I have that exact same set up but the codes are never stored after I get a CEL even if I'm checking them while its happening

UPDATE: Ran the codes again, this time managed to get a P1391 Wheel speed sensor and a P0340 Camshaft Position Sensor "A" Circuit code. I've already replaced the Cam sensor already with a Mopar one, but, that still doesn't really explain the clunking and the sudden feeling as if the Jeep wants to go in reverse at 60mph+. Scariest ride I've ever had in an XJ LOL

 

So you obviously have ABS...have you checked all your wheels/brakes, etc? Maybe you have a broken caliper bolt or something like that.

Noggin pokin time
😜

 

Not going on much, but I would check for a ground fault that resets a bunch of things like the ECU and the ABS.

I had a somewhat similar behavior on my Subaru except mine happened when I touched the brake pedal. Not pushed it, any touch at all would shut off the engine for about 1 or 2 rotations, reboot the radio, blink all the lights. No codes. Turned out to be a battery connection corroded through. Started fine, but somehow it would glitch everything by lighting the brake lights. That took a minute to track down.