Need more help with a FORD

[sneitzel]

My buddy has a 2001 F-150 4.2L V6

He got an SES light the other day and the truck is running "like hell".

AZ scanned it and got 2 codes:
P0171 Bank 1 lean
P0174 Bank 2 lean

Their evaluation says either O2 sensors (there are 4) or the MAF.

My question is other than just throwing parts at the problem how can we narrow this problem down? If it is an O2 sensor how can we tell which one? As I said there are 4, 1 pre cat and 1 post cat on each side.

Any input would be appreciated.

[Jeff_in_Atl]

My first thought was the fuel filter. Low fuel pressure will cause it to run lean. I'd start by checking the fuel presure.

I have a friend who was going to Florida and on the way his F150 died. He is a diesel truck mechanic so it didn't take him long to figure out it was a clogged fuel filter. He replaced it and he was on his way.

[Trash man]

clean the maf, those were the type of codes i used to get on my dads t-bird when the maf got dirty

[sneitzel]

Great ideas guys, Thanks.

Gonna work on it this weekend and will try those things before we start throwing parts at it.

Any other tips?

[BrdWAtti2d]

Any other tips?

Trade it for a GM?

[sneitzel]

Trade it for a GM?

I'll pass that one on to him.

[Trash man]

get some CRC MAF cleaner and long wooden q-tips and spray the cleaner on the q-tips and gently clean the maf. then after u do that, spray it on the wire itself to make sure its 100% clean

[sneitzel]

My first thought was the fuel filter. Low fuel pressure will cause it to run lean. I'd start by checking the fuel pressure.

Replaced fuel (and air) filters and it is running great.

Good call Jeff!

[Jeff_in_Atl]

Replaced fuel (and air) filters and it is running great.

Good call Jeff!

Glad I could help.