- Joined
- Oct 22, 2008
- Messages
- 1,701
- Reaction score
- 18
- Points
- 38
- Location
- Michigan
- Vehicle Year
- 1999/1984
- Make / Model
- Ford
- Engine Size
- 4.0 & 2.3
- Transmission
- Automatic
Well I'll get straight to the point. My 4.0 OHV is pissing me off, lol. For a while now, I have been getting shit fuel econ, around 11-12.5 mpg and after running for a while say after i get off the highway or after running the trails for a bit, it will start to stutter, lose acceleration, drop below 1000 rpm at idle, gets pretty nutless. I can floor it and it will shift down and stop doing it for a while and i can shut the truck off and restart it and it will stop for a bit. But No matter what, I have been getting 11-12 mpg, and thats pretty outrageous with stock tires which im running for now. What I have done (procrastinator woooo) new motorcraft plugs and wires, plugs gapped to .54 and cleaned my MAF, new fuel filter, and sprayed carb cleaner everywhere and the RPMs didnt jump so i dont think its a vacuum leak. Its throwing two codes. P1131 = Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1 And P1151 = Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2 Where to next?