Hello guys, I have a 1997 F350 HD with the 5.8L Gas motor and I recently did a tune up on the truck. I am talking about spark plugs, wires, coil, and cap and rotor. After this I had the check engine light with codes P0174 and P1131 come up. Just found those tonight and will be cleaning the Maf tomorrow as well as changing the fuel filter and checking for vacuum leaks.

Any other Ideas why my truck is running lean? it didn't have these codes before the tune up.

 

Not sure what those exact codes are, but if it's running lean, I'm curious when the last time the o2 sensor was changed out? Not always, but many times the o2 sensor is the main reason for rich/lean conditions. But if yours is running lean it could also be a vacuum leak.

If there's more than 50k on the o2 sensor, I would just recommend replacement. That's about all they're good for. And if you do replace it, make sure to reset the computer [unhook battery for 15 minutes] and then take it on a 20-30 minute highway drive that includes as steady a throttle as you can provide. New o2 sensors need to be calibrated for the computer and the drive is what does this.

 

Both codes are related to a dirty or contaminated MAF sensor. Cleaning yours is the first place to start.