My 99 XJ is feeling sluggish lately. It dont miss or sound rough just feels low on power than what it had. I pull a trailer with a fourwheeler alot and thats when I first noticed that it didnt have the go like it did. I just put new wires,Plugs,dist cap,button and all that on it back in the winter. Its really depressing me. Two things come to mind. Fuel and exhaust. Oh and I also seafoamed it in the winter. Ideas??????????????????????

 

Cat could be plug or seafoam killed the first O2 sensor.

 

I have read here, and other forums that a clogged cat could cause loss of power and sluggishness

 

The cat has just been on it since winter also. If the o2 sensors was shot wouldnt the CEL be on?

 

new cat before or after seafoam? i got my xj for 300 dollars because the PO couldnt figure out that it was the cat that was keeping it from going over 45. believe me a clogged cat can be hell on a vehicle, and ive heard that if you seafoam, sometimes even with a new cat, that it can clog it if you had alot of carbon buildup and such.

 

That crossed my mind. But I done that on Dec 27th. I think it would have shown up before now but ya never know I guess. I did do it after the cat was on and It didnt smoke as bad as I thought it would from the videos I have seen after seafoaming. Maybe it was getting caught in the cat. Damn what to do now. I dont wanna start fudging with the exhaust again.

 

just take the cat off and see if theres any difference.....although the lack of backpressure could make it sluggish anyways

 

Yes thats what I am afraid of. Thats why a put a cat back on to begin with. What about putting a glass pack muffler in place of the cat? Would that put the back pressure back without having the proneness to stopping up?

 

temporarily yeah that would work to test it, but i dont recommend leaving it off

 

I gotta figure something out. THe loss of power is driving me nuts. I dont think fuel or spark is my problem. Whats the best way to test the fuel pressure to see if its up to par?

 

I ran a test without the Cat on. It was 75% clogged up so it wasnt helping. It didnt restore the power that it had. No Check engine light is on either. Could my Front o2 sensor cause it to run so sluggish? Its killing me.

 

How about sensors? Maybe a crappy tune up? I want the pin you in the seat power back!!!

 

Check your flexplate! My 91' was acting the way you are describing and long story short it ended up being the flexplate.

 

Did it make it have almost no bottom end torque? Top end still okay? I do have a small noise that I have always thought was the Flexplate. Not sure but It depresses me.

 

Near as I can tell I ran it like that for at least 3yrs. Went through DEQ 2 times with not even a hickup. It just kept getting more and more gutless. Took it to 2 seperate shops and they couldn't find the problem. No codes no lights. Finally melted the exhaust manifold cause it was running so rich. When I replaced the exhaust system it had absolutly no power. Put it on the rack and just about crapped myself when I saw my new exhaust glowing. Lots of money and time went into finding the culprit. Pull your inspection cover and get a good flashlight and a mirror so you can see way up in there. Check for cracks and look closely at the bolts to the crank. Mine was literally center punched and wedged. It would advance every time I started her up. Good luck!