well a few days ago i was pulling out of work and was waiting for a buddy ... had my truck in drive just sitting there ( 04 f150 fx4) and it stalled . it started right back up and seemed fine ... the engine light came on and stayed on ... when you start it , it runs fine but then its almost like its not getting its fuel it want to drop its idle to almost below 500 rpm ... when i give it a shot off fuel it seems to help it for a minute or 2 ... any suggestions would be greatly appreciated... hoping to not have to take it in and put it on the computer.. thanks

neil

 

Without knowing the codes, it is guess work.

Take it to Autozone and they will scan the codes for free.
Get the actual codes, not what the guy thinks is wrong.

 

Yep, you need the DTC. Auto Zone will give that to yuh, "Free". Make sure you write down the code and post back.

 

I had it put on the computer abd 2 codes came out

- P0170 , system too lean bank 1
-P 0174 , system too lean bank 2

The computer also said that all the sensors were fine . Any help or advice is greatly appreciated for I am a do it yourself kinda guy.


Thanks Neil

 

98% probability of a intake vacuum leak.

 

Do you have an aftermarket intake?

How many miles on the plugs and fuel filter?

Have you ever cleaned the MAF and throttle body?

 

No aftermarket parts under the hood at all... Magnaflow muffler is it , plugs and fuel filter ... Bought the truck with 60kms now have 150 , planning on doing both of them this weekend ... Little nervous with the plugs but I'm gonna give it a whirl .

 

That's PO171, you must be typing from a phone lol.- What engine is it Neil ?

 

5.4 4x4 and yes an iPhone

 

Someone posted what it is most likely, yea projectSHO89 above.

 

If I were to do a gotts intake mod ... I think that's what it was called , do you think that might clear up a vacum issue?

 

No, not related.

 

Ok last night I tool my maf sensor out cleaned it. I also took off the throtle body and cleaned it out . The truck seemed to work a little better obviously but the Problem is not solved . It runs fine on the highway and also when it's cold. As soon as I come to a stop when it's warm it wants to quit unless I feather the throtle. I checked the vacum lines all seem to be good. Planning on doing the plugs and fuel filter this weekend . Hoping that might solve it. I did some reasearch and found a guy with very similar symptoms ... He ended up solving it with valour management Valve .... Anyone know the whereabouts of this or that maybe this is possibly the problem as well?

All input is greatly apprecited

thanks Neil

 

See post 5 in this thread.

https://www.f150online.com/forums/20...-stalling.html

If you use the Advanced Search, there are sevaral threads to check out.