P0171 and p0174 on 4.6 2005
#11
Senior Member
Not sure if it's been mentioned, but, if you're getting a gas smell, check to make sure your plugs are all torqued in properly. They have a tendency to loosen up in the 4.6 from what I've read.
#12
Senior Member
Don't forget about the FPDM. That's the Fuel Pump Driver Module. It's far more likely to go bad before the fuel pump. When you drop the spare tire, it's bolted onto the frame rail right in front of the spare tire. Take it off and look at the metal part. They have a tendency to corrode, leaving the circuit board exposed to water.
#13
Senior Member
^^^ also that. One or more loose plugs will introduce a lot of unmetered air, causing the truck to run lean.
#20
Junior Member
I have this same issue with my work truck '05 xl 4.6 4x4, it's at the motor pool now I'll let you know what they come up with, but I went through the vac system, replaced the pcv valve, removed and cleaned the maf and cleaned out the throttle body. It's not my truck belongs to the P.D. so I couldn't go any further than basic stuff.