I just bought a 2000 Ranger 4x4 with 4.0, auto tran. 157k on it. I bought it knowing it had issues. I drove it home 15 miles and it has no power and will not climb hills very well. Also missing pretty bad, not as bad when idling. After reading up on the many possible causes, a bad cat may be the culprit. ?
So if I loosen the connection at where the cat meets the header and take it for a short test drive, will I risk damage to the engine? And do you think this is a good way to test? Will I have to put a new gasket in when closing it up?

Thanks everyone.

 

its not a good idea, as the trucks o2 sensor are near the cat. so it may run worse. do a neurtal test. revi it up and have someone stand at the tail pipe, see how she blows out. drilling a hole in the front of the cat is a quick fix if its plugged.

 

Thanks, well she blows, but I'm not sure what kind of pressure Is considered good. I will talk to the muffler shop on Monday, maybe there is a way to test it?

 

rent an exhaust backpressure gauge. The back pressure should not exceed 1PSI at idle, 3PSI during 3-4 WOT snaps or 8PSI at WOT under load...instead of drilling a hole in your exhaust as mentioned above, you could always unscrew both upstream o2 sensors and see if it has more power...The cat on your truck has 3 nuts at the y-pipe. you can also remove those nuts and tie the exhaust up out of the way and see if your power returns