Bad MPG on my 2001 Cherokee

[YtseJam454]

Well that was kinda my point. This guy is going to change his cam sensor (god knows why) and 2 O2 sensor when only your precat O2 effects fuel management. A diagnosis by a competent tech will actually save you money when you start throwing parts at your car...And your fuel trim is your computers programmed air fuel ratio vs actual interpureted air fuel ratio. By looking at other factors it can help you pinpoint a problem...

[sneaky7980]

Installed the cam sensor, took about 3 minutes and attempted the o2 sensors. The 4.0 in my 2000 GC has 2. The forward one took a while just to unplug due to location of connector and the rear was a peice of cake. Started it up and it ran terrrible. Got a code for "O2 sensor voltage above normal operating range". so i put the old ones back in, still ran terrible. reinstalled the old cam snsor, same deal. I even drove it down the highway thinking that maybe the computer neede to reset or something but nothing changed.
I know this doesn't help any but i said i would post results.

[sneaky7980]

First, a response to YtseJam454,

"This guy is going to change his cam sensor (god knows why.)"

I had to change the CAM sensor anyway, CODE P0340 NO CAM SIGNAL AT PCM. I guess i should have mentioned that i wasn't changing it for fuel economy purposes.

Second, I was changing the 02 sensors at the advice of a lot of people and because it is cheap and easy. I've always heard that they can affect fuel economy.

2000 GC
106K

[mikey531]

Ever think someone may be siphoning it out of your tank ?