My 1998 cherokee will not get above 2000 rpms. At 2000 rpms it bogs down then if I give it more gas it will stall. I have changed the tps and replaced all three shift solenoids. That has not worked. Please help it's my dd. Thank you!

 

Any check engine light? If so, you must pull codes and post them here for comment.

Have you verified fuel pressure yet? A marginal fuel pump should be ruled in or out at this point.

For a 98, you should have 49 psi, plus or minus 5 psi at idle. Can only be done with a fuel pressure gauge installed on the schrader valve on the fuel rail.

 

No check engine lights. Will have to check fuel pressure. Thanks for the quick reply.

 

sounds like a clogged Catalytic converter to me...

 

Somebody else said something about a clogged cat. How do I check it?

 

ahh cant help you there. my idea would be to cut the exhaust off before the cat, or remove it somehow to see if theres a difference. Then if theres not, i'd have it welded back up.

 

You can check for a clogged cat with a vacuum gauge or by checking the temp before and after with a laser thermometer. If you hook a vacuum gauge up rev it. It will drop to about 5" and if the exhaust is clogged it will come back up really slow.

 

I drilled and tapped an M6 hole (1/4"-20 or 1/4"-28 would do too) into the pipe before the cat and fit a short hollow threaded stud (I drilled a bolt and cut off the head) into it as a nipple for my pressure gauge. As mentioned, pressure built up to about 12psi at a fast idle and off the gauge when reved. Cat was melted and plugged from over-rich condition from a bad O2 sensor, ruined by a headgasket failure. Replaced the cat and sealed up the hole with a short M6 bolt.

Temp gun works, but a pressure gauge is instantly believable. Good cat doesn't go over 5psi at full throttle.

Steve

 

Clever Steve /\. Little more work than loosening the header pipe nuts for a minute, but clever.