My check engine light is on. The vehicle runs well. The OBD2 scanner brings up the codes P1172 fuel air metering and P1179. I have had several mechanics look at it. The last was a rover specialist with an auto logic scanner. They say that at an idol it does not have the proper fuel air mixture. After having it for two days they could not fix the problem. Since then it has new plugs and wires. Cleaned the K&N air filter. Even changed the mass air flow meter. Still the codes read the same. Any ideas!

 

First, what year is the truck and how many miles?
Second, don't run a K&N with a Bosch MAF on a D2, it will kill the MAF.

Here are your 2 codes,
P1171 Oxygen Sensor System Too Lean Fault Banks A & B
P1172 Oxygen Sensor System Too Rich Fault Banks A & B
P1176 Maximum Positive FMFR Correction Fault
P1177 Maximum Negative FMFR Correction Fault
P1178 Maximum Positive AMFR Correction Fault
P1179 Maximum Negative AMFR Correction Fault

1179 is considered a major fault, I have seen iot before and have no answers in what to do with it.

Wish I could give you some more info, let me know how it turns out.
Mike

 

ditch the k&n filter for starters

 

What year and mileage? I agree with the filter. Ditch it. If you have a D1, I think the Sagems MAF is mare sturdy, but I am not risking it myself.

 

I have a disco 1 1997 4.0 78000 miles. Been working on this problem for two years and around 10000 miles ago. I will ditch the K&N.