Well since I have a rover scanner now I decided to reinstall the original ecm and reset the adaptive values, I drove around , drove to va , and to work for 2 days had the 1179 has not returned

So was it the other ecm being screwy? Thoughts?

Well, since the 1179 is an adaptive value you basically reset that counter back to zero which doesn't happen when you reset the CEL as with a generic scanner. This long term fuel trim fault is the ability of the ECM to "adapt" to your upper oxygen sensors inputs, it's more dependent on your oxygen sensor condition (and overall motor's tune) than the ECM's ability to counteract/correct their readings. The second ECM, was it off an AEL truck?

Yes same Ael same year, I would think I put enough miles on it to retrip it though? Vehicle runs the same like there is nothing wrong ( except the usual no power 4.0 complaint)

Guess I will just keep an eye on it, I know the o2 can't be crossed cause it would run bad

Maybe the engines just beat needs rebuild?

What are your O2 readings?

Will look tommorow last I looked the up were fluctuating normal

I did not check the o2 but I did fill up, I just got 12.1 MPG I have ben getting 9 previously???

Scouts, startup open loop both upstream sit at 1.020 ? On the ug closed loop they both fluctuate correctly

I don't see a problem with the O2's. I don't know if they have the machine over here yet but in UK they have a machine that cleans out the carbon to lower the carbon emissions for their MOT - to pass it. Hooks up to the fuel injection Schrader and they remove the fuse for the fuel pump and hook up the fuel return line back into the machine so it's a fuel loop through it. Two cans of high test cleaner and about an hour of running at 1200 rpm it's decarboned the motor. I think if somehow you could remove the carbon you'd see better mileage and you might not chug up hills as bad.

I'm running a stock thermostat so my motor stays really hot - better atomization of the fuel and it runs like a top up hills once warmed up. It's probably one of the most crucial reasons I get nearly 18 mpg throughout all seasons - keep the motor cleaned up by keeping carbon to a minimum running stock gear.

Yeah I am on a stock stat right now and my fan switch comes on at 215*f, I can't have much carbon I cleaned everything when I did the heads?