2004 f150 5.4 liter p0172 p0175

checked maf g/s at idle had 5.5ish baro reads 150hz. im in ohio. checked fuel pressure pid on scanner read 40psi. checked for stuck open purge valve. the numbers go rich at idle but they look fine driving normally. any other ideas

o2's are not stuck rich or lean

cheryl hartkorn wrote: checked maf g/s at idle had 5.5ish baro reads 150hz. im in ohio. checked fuel pressure pid on scanner read 40psi. checked for stuck open purge valve. the numbers go rich at idle but they look fine driving normally. any other ideas

150Hz, eh? Did some quick Google work, says Ohio is anywhere from 500 to 1,500 ft. 150Hz is more consistent with something around 3000 ft? The BARO calculation isn't perfect, of course, but maybe something there?

40 PSI fuel pressure sounds right for this truck. Any other symptoms, or just the "money light"? Just curious, how far negative are the trims at idle?

Thought for a second about an intake restriction, but you'd think that would cause the fuel trims to worsen off idle... I seem to remember a PCM reflash out there for this code and this engine on Econoline's, maybe it applies to this truck, too?

Is this a Flex Fuel vehicle? You might want to check for E85. I had a Ford Ranger with a v6 (can't remember the size), where I had to Re-write the PCM software to fix a similar problem.

tyler both banks were around -25 for short term. not really any other symptoms.

cheryl hartkorn wrote: tyler both banks were around -25 for short term. not really any other symptoms.

Gotcha. I had a glance at some data I got off an '05 F-150 that I looked at recently, just to have something to compare to.



www.scanshare.io/share/LSMwrX9cbEy44uGhyucV4Q

I did notice that the MAF g/s is higher on my capture than on yours, around 7 g/s compared to 5.5 g/s. Thought I was onto something, but I don't think that matches a rich condition? Your MAF would have to be over-reporting to produce a rich condition, rather than under-reporting. Oh well

im going to find a place to tap into the fuel system to hook a fuel pressure gauge into and compare to what the fuel pressure sensor reads. do these use Schrader valves??

Not sure, though I figure they would, given that the Duratec V6 returnless systems have a Schrader valve.

Ro-longo wrote: Is this a Flex Fuel vehicle? You might want to check for E85. I had a Ford Ranger with a v6 (can't remember the size), where I had to Re-write the PCM software to fix a similar problem.

I think that's a valid point. If it is a flex fuel engine, I imagine there will be PID in the list somewhere corresponding to the amount of E85 it "thinks" is in the system.

Just thinking out loud here, wondering about IMRC system. Wondering if it's possible for the motor to be changing position as designed, but the linkages to the runners are disconnected or reversed...

does the 5.4 use those? but in my experience every imrc code I got was an unhooked linkage. so I imagine there would be a code pending

cheryl hartkorn wrote: does the 5.4 use those? but in my experience every imrc code I got was an unhooked linkage. so I imagine there would be a code pending

I thought the newer ones did? The 5.4L in that scan data capture I posted did, anyway. :huh:

Is this the intake style where the throttle body sits horizontally, with the flat air filter that gets inserted into the intake tube on a plastic carrier? I've seen missing or damaged air filters cause rich codes on those designs. One of those cases when the filter is required to create laminar air flow over the sensor.

2004 was the split year for the F150. They could be had in the new(er) body style or the old style, like a 99. They called that one "Heritage". Get in it with customers over that all the time...

Purge valve stuck open?

How'd you go with fuel pressure?

checked purge valve noah. one of the first things I did. im going to reflash the pcm. there is an update available. haven't checked fuel pressure to compare to the fuel pressure sensor. haven't done an injector balance test yet.

cheryl hartkorn wrote: checked purge valve noah. one of the first things I did. im going to reflash the pcm. there is an update available. haven't checked fuel pressure to compare to the fuel pressure sensor. haven't done an injector balance test yet.

I got money on the reflash

Ok, let's make this interesting. I'll put SFA on a lying fuel pressure sensor.

matt.white wrote: Ok, let's make this interesting. I'll put SFA on a lying fuel pressure sensor.

I'm not positive what an SFA is, but sure, you're on! :lol:

Sweet F all. (Not much in other words)

I may have to send you guys an Aussie slang dictionary.