[LOCKED UP]

I took my YJ (it has a 98 TJ motor but 91 computer) out for a spin today for the first time in a month or so. The first 15 minutes were fine, other than the boggers warming up.
After that, as I'd let off the gas in gear or if I was just coming back into the throttle to shift up it would sorta buck in the lower gears. It didn't completely stall but I could tell it wanted too.

Also, I recently removed the muffler and put a turn down until I can get a proper cat back system put in ... I don't know how it could effect it but if yall have heard of anything please let me know.

I figured out how to pull codes with the whole flashing light thing.
I'm pretty sure I got:
12 - Battery dissconnected recently
17 - Engine stays cool too long (bad thermostat or coolant sensor)
33 - Air conditioning clutch relay circuit open or shorted

So:
12 - Duh
17 - I did notice it runs very cool. I'll try a new thermo (where is the coolant sensor?), but would that really cause it to sputter?
33 - Not sure what this means. I don't run the A/C in there & it's not even hooked up ... anyone know how this could be effecting me?

Anyway, here is a list of potential causes I have found via the net:
clogged Cat
TPS
IAC
MAP
Camshaft Sensor
O2 Sensors
Plugs & wires
Cap & rotor
Loose Grounds
Crankshaft sensor
Fuel Pump
Injectors
Fuel Filter
Bad gas
Alternator

I'm on the same tank of gas for awhile, so that's not it. Plastic tank too so filter is probably OK. Throttle body is very clean on the inside so I'm thinking it isn't carbon buildup or anything on the TPS/IAC

I think I'm going to try to replace the O2 sensor first. Then the thermo &/or coolant sensor. I was also considering gutting my cat. Does anyone see any potential issues (other than smog) with me gutting the thing? Will there be too little backpressure or is that just internet lore?

[superjustin]

I had the exact same problem about 2 months ago. I got a BG Induction Service Clean and it solved the problem. They said I just had a dirty Jeep.

hope this helps.

[flame0086]

I had this problem on my 91 (with a 91 motor). It was the throttle position sensor (TPS).