MackyD

Been having some problems with the jeep lately. Started with all the recent cold weather. The jeep would start up, kick through a couple rotations and die. If i applied the gas while starting it would keep running, but die as soon as I let off the gas. It would continue to do this until it got warmed up, at which point it would run normally. When it did start and hold idle, the engine would run very rough for a few minutes until it warmed up. It is also slow and bogged down when accelerating, and slow to return to idle RPM when I take my foot off the gas. This occasionally continues after it warms up. When i turn off the jeep, I often smell unburned gasoline when I get out, leading me to believe the fuel mix is running rich.

Yesterday was the first time i've seen a CEL come on from this behavior. Code came out as P0133, which i believe is slow response from upstream O2 sensor. No other codes. The guy at AZ says it is likely a fuel line/ injection issue and not a bad O2 sensor, but I'd definitely like a second opinion.

Roler

Sweeping the back of the forum again:

Well, there seems to be an issue with your air-fuel mix alright.
Appears that when you apply throttle (thus increasing the 'air'), it is not followed by the correct adding of the fuel, causing the bogging down when accelerating.
The application of throttle to keep it running after startup but dying as soon as you let go, actually would indicate the opposite (too much fuel not mixed with enough air), which makes it interesting. But the slow return to idle, is a clue towards something which could be involved in both: the TPS giving incorrect readings.

So, what I would do to check the above (and narrow things down a bit) is:

clean the throttle body/valve
clean the IAC
Do a fuel pressure reading
Test your TPS (an analogue meter is best, because this will give you a 'visual' on the gauge 'sweep', looking for dead spots. Do a search, it has been described in several threads).

See how this goes and let us know (if you're still following up on your own thread)