[Tdad]

My 97 TJ (4.0) has been acting weird lately. A couple weeks ago, it bogged on me when starting out when it was cold. Step on the gas and it would slow down. Put the clutch in and it felt like it wanted to stall. Rev the engine and it was OK. Only did this in the first mile after being started.
Now it seems like it's getting worse. It doesn't bog down, but it feels like I need to be giving it more gas than I should have to. When I let off the gas, it doesn't feel like it wants to coast at the same speed but instead slows down.
So far I've cleaned my air filter (K&N), cleaned the throttle body (wasn't really dirty) and put a bottle of injector cleaner in the tank. That actually seemed to help for about a week.
No check engine light.
Any suggestions on where to look next? Thanks guys.

 

[Odhinn]

Two possabilities off the top of my head, Fuel Filter or Catalytic converter. Both will give those symtoms Maybe someone esle on the forums has more ideas on it though.

 

[ccarr51]

is it throwing any codes? Mine was doing the same thing because my TPS sensor got wet and shorted out. My jeep actually did stall out when i put in it reverse and started backing up. So that may be your problem if your throwing any codes and that an easy fix.

 

[mrbigjeep]

check your cat also

 

[amerijeep]

check your cat also

Man, I had like a dozen jokes and off-color comments pop into my head as soon as I read this.

 

[mrbigjeep]

lol i thought someone would

 

[Tdad]

I have a dog, not a cat - think that could be the problem?

Sounds like that might be where to look though. It's got 105k on it, both O2 sensors were replaced less than a year ago. If it was throwing a code, the check engine light would be on, right?

How do you diagnose a bad catalytic converter? (I didn't say cat jokesters)

Do I have to drop the gas tank to change the fuel filter? Sounds like a PITA.

Thanks.

 

[Odhinn]

Faulty O2 sensors are one of the major causes of Cats going bad. Really only two way to diagnose a cat without a computer to read the o2 sensors output, First Unhook the cat from the system and see if it runs better, the other is drill a hole in the cat and see if it is better. Since you say that the o2 sensors were replaced less then a year ago, Im assuming because they were bad and were flooding the cat with fuel. I would guess that would be a pretty good place to start. On your fuel filter, off the top of my head Im not sure where it is. Some are on the frame rail some are on the firewall. Maybe someone with a 97 will pop up and join in for an exact location.

 

[mrbigjeep]

air intakes burn up o2 sensors fast...well faster than normal anyway