97 TJ running rough

[Jacwelch13]

So the past few months I’ve been having problems with my Jeep running poorly. It’ll start up just fine and I’ll get on the street but once I get to 2nd/3rd gear it’ll seem to bog down/lose power. I can have the pedal all the way to the floor and nothing will happen.

I’ve recently replaced plugs, wires, cap, rotor, TPS, crank/can sensors, and fuel pump but nothing has seemed to help.

any ideas?

 

[TJ4Jim]

May want to check out your fuel pressure and the 97 should have the fuel rail outlet for a test gauge.

 

[Jerry Bransford]

Running well when cold but bad when it starts to warm up points to a bad upstream O2 sensor. That's the sensor the computer uses to set the air-fuel mixture. The computer doesn't refer to the O2 sensor for fuel mixture purposes until the engine starts to warm up.

Replace the upstream O2 sensor just under the exhaust header (not the one on the catalytic converter) with an NTK brand O2 sensor. Do not get talked into a Bosch O2 sensor.

No guarantees but this is what I'd do if my TJ had that problem.