something weird

[dakal]

since i bought this jeep three mos ago, all i've done to the motor is spark plugs, and magnacor wires. then i pulled the air cleaner off, and stickie and gummie it was. checked the tps and idle control , same mess. cleaned well and mpg went to middle 14s. but my mileage has been in the middle 14 's- so i found out the oxygen sensor was shorting so it was in closed loop all the time. someone broke the pin for the temperature sensor so i replaced that also. my idle went to 1500, so i adjusted it to 850. everything helped, but stepping on the gas accelleration was bad. so i took the exhaust system off and looked in the cat. hooray for big pry bars. put it all back , what a difference. idle speed was bouncing around before i did the cat, but after driving few miles, stopping and cooling it down, started it up idle was great. between here and naxja forums, i learned a lot. had no experience with i-6. i'm going to check the tps voltages and adjust if necessary. i have the cracked exhaust, must fix{ $}

going to drive it on the freeway 75 mph for fifty miles to clean it out, then i'll check mileage and live with it. anyway, i had no idea that cleaning out the cat would make such a big difference. :brows:

[jared]

don't expect good mileage from the 4.0, but they have good torque.

 

this guy has a site page about them. http://www.jeep4.0performance.4mg.com/

[Pete M]

A good cat won't affect anything, but a bad cat will choke the life out of an engine.

[dakal]

ya i know dino's site, thanks, also go jeep is good. eagle- i went to gibsons site and listened to the muffler. good sound. when i replace cracked exhaust i'll change pipe and muffler with their's.

[HOrnbrod]

Amazing it wasn't running hot with a clogged cat. Mine did on the old engine (after I replaced virtually everything in the cooling system). The cat was clogged at the inlet with thick gummy tar-looking crap. Put in a new stainless aftermarket cat and replaced the O2 sensor for the cure.