BJ's got it. It "reburns" anything that hasn't completely burned. When your jeep is running it is basically just converting Hydro-Carbons (HC, Gasoline) into CO2 and H2O. When it breaks the HC into CO2 and H2O a lot of energy is released as heat. Theoretically nothing else should be evolved from that combustion. Unfortunately, engines spinning at thousands of RPM's are hardly ideal libratory environments, and sometimes the gas doesn't burn all the way forming CO or not at all passing some HC or burns way to hot forming NOx. All the catalyst does is re-combusts the CO/HC to form CO2 and rips the N Off of NOx to form N2 and O2. A 3 way cat. does both NOx cleaning and HC/CO cleaning, a standard oxidation cat cleans just the CO and HC, no NOx. pretty much every car on the road today is a 3 way cat car.

So because the cat re-burns the un-burnt/partial-burnt fuel, it makes heat. If you have a miss, or are running rich, it will make enough heat to liquefy itself. This is why auto manufactures switched from points to electronic/HEI, as an insurance policy for thier new cat's, not for "performance" or HP gains.

Since this problem started right after you took it muddin', I'd pull the distributor cap off to make sure you didn't get some moisture in there which would make it run like crap.

alright boys, well i cut my cat off today (might i say that I4 sounds beastly) but the problem still occured after about 20min of driving i will clean my distributer cap tomm. as i am off of work. but if that doesnt work what should i lookin into next, fuel pump...where is my fuel filter located so i can examine that also.

with it being so loud i was able to notice something else when the problem did occur like lets say a small hill climb after 20min of driving or less... it would sputter then even if i put the pedal to the floor i noticed at one point there was no fireing at all..atleast that i could hear.. it would be silent but when i let off and back on again it would fire but sputter still and cant do the hill without turing off the jeep and waiting for sometime.. i guess i should change out my spark plugs which i'll do this weekend hopefully if a certain someone allows it.

Try unplugging the O2 sensor and see how it drives around.

I just went through the creek crossing at Pismo beach the other day after a rainy spell and was about half up the doors. From then on the engine ran like crap. Turns out the O2 sensor decided then would be a good time to die. IF it is the O2 sensor, it will be an immediate fix. I would also check the crank and cam position sensor's and their connectors.

where is the O2 sensor on a 94, 2.5l

Sunder would the 02 sensor turn the thing completely OFF? He sez at times he couldn't hear it run with open exhaust... If he had said that before now I would have said FUEL FILTER sorry I did not get the hint till now.. But FUEL FILTER does just zackly that..
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

how to check it jimbo?

If you cannot remember when you changed it... what the hell spend the 6 bucks..
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

If the O2 sensor was sending the worng signal it would cause the motor to run WAY out of spec. When my O2 sensor was dying, it would sputter stall out then slam back on the power. Un plugging it will take it out of the loop, causing the car to run on the sensor's it uses in open loop (when cold). the sensor is located after the exhaust manifold near the first bend in the pipe.

so this weekend before work i will bring the girl over (So she feels she gets attention also.) and change my spark plugs and fuel filter before work just for the hell of it. ONLY after driving the jeep with the 02 sensor to see if that is the problem. but again where along my fuel rail should my filter be? and is my fuel pump still outa the question as a problem here?