frustrated
New member
I have a 1998 Jeep Cherokee 6 cylinder 4.0. My front o2 sensor keeps going out. I had this problem a while back and it is happening again. I just had a tune-up and replaced the sensor 2 weeks ago and now it is out again. Exhaust running rich and black stuff out the tailpipe. My cat conv is gutted. Not sure why this keeps happening. Been to several shops. Any ideas?