steckarex

Alright, so ive been having trouble lately...my trucks been sluggish (1998 4.6L V8)
I had it scanned and the codes- PO171(Bank 1) and PO174(Bank 2), "System Too Lean" -came up.
What do these mean??!!, cause i have absolutely no idea of what to do to solve the problems.
Thanks

transmaster

Everything you ever wanted to know about these two codes can be found here: http://www.aa1car.com/library/ford_lean_codes.htm

Stomper

Well that reading comes from the 02 sensors . Either the truck is to lean and they are reporting the truth . This could be from the mass air meter , a cold air intake , intake leak , a vacuum leak or something like that . If none of those problems exist it could just need 02 sensors but the fact that it is saying both banks are lean points toward one of the things I said before . Start by cleaning the mass air meter . They sell a spray that works well . If that doesn't help get some carb cleaner and spray it all around the engine compartment while it's running . If you hit an area and it revs up you have an intake or a vacuum leak . Pay attention as you spray so you know where to look for the problem and don't get the carb cleaner all over the paint .

My guess is a vacuum leak , look for a broken or missing vacuum line .

JasonErnest

I have had the same problem. Also a '98 F150, same engine codes. Started as just one bank and I didnt notice any power or gas mileage dropoff so I didnt do anything. Then both banks came up. Fixed a vacuum leak and thought that fixed it but now the engine light came on again.

Is it possible to put hose clamps on too tight and seal things too much? When I start the truck it makes noise like it's gasping for air. If I switch on the defroster, it pulls so hard that the engine will die if I'm sitting in park. Makes a loud mechanical sucking noise, RPMs drop instantly, engine chugs and stalls. If I flip the defroster on while driving and can give it gas to stay running, the system just makes an awful straining sound. Can something be choked or too tight? Thanks.

Stomper

The defroster actually uses the a/c pump (if you have a/c) and that makes more sense as far as the stalling goes . Does the A/C work properly ? If not possibly the pump is going bad . As far as having vacuum lines too tight , no that isn't an issue . Possibly hooked something up wrong and still have a leak . That is a strange one you have happening there .