97 with P171 & 174 running lean

[Woodsman]

twizzler,

i used some of the black high temp RVT from any parts house.

 

[Woodsman]

It's FIXED

I've been 400 miles without the light on through at least 10 drive cycles. Turns out when I replaced the MAF and the engine fell on it's face it wasn't because the original MAF was bad, and the new MAF was good. It was because the orig MAF was good and I believe the new MAF had a different resistor than what was suppose to go in the truck(possibly for a 3.0?).

I got to thinking how the engine runs great after the intake package, but still says its lean. And how the only other part swap that changed how it ran was the MAF. I've driven 400 miles with the original MAF, when the light would religously come on before within two drive cycles previously(independant on miles driven). Just returned the "NEW" MAF and got my $150 back. The new vacuum lines will stay on to prevent future leaks, along with the new($50) EGR valve that was gummed up a year ago.

I hope this helps other's with this problem. No offense to any parts guys out there but from working at 5 different shops and dealing with countless parts store employee's i've learned not to put a whole lot of trust into the parts industry. Earlier in this job I also ran into the wrong valve cover gaskets at 2a.m. upon pulling the old gaskets.

Both of these parts the FORD dealer in town didn't have and I bought them at the "best" parts store in town APC, that was recommended by the parts manager at the ford dealer.

ALSO another heads up I bought a TOPAK T-280 scanner off ebay, A COMPLETE JOKE! Not only will this scanner give bogus(if any) readings for MPH, VIN, all O2 and Fuel trim readings, the "LIVE DATA" is a joke. I used a buddies snap-on RED BRICK scanner to make sure it wasn't my truck. It is basically a freeze frame that you try to read in 5 seconds, then it "updates" for 10 seconds while you wait.??? Then you get another 5 seconds to try to scroll through the readings. Not very LIVE. This scanner will be sent back tomarrow and I'll be in the market for a more expensive, name brand scanner(MAC, MATCO, or SNAP-ON). Possibly try out the nicer scanners at the parts stores.

Anyway I hope yall get some good info from this, and I'll post back if my problem re-occurs. Good luck diagnosing!

 

[BeaterMan]

fuel pressur regulator? that can cause a lean condition on BOTH banks.

whoops, got ahead of myself and didn't realize that ur good to go now.
yea i would love to have a "nice" scan tool- when i was doing auto we used a mac mementor and a mastertec. that mastertec could do anything you wanted to and then some but with the 5-6k price tag i'd sure hope it could.

 

[OBX2003]

I had the 171 and 174 codes on my 03 4.0. I finally found the vacuum leak. On the passenger side, pretty much obscured by the radiator hose, there is a large vacuum line attached to the intake with a rubber elbow. Once I moved the radiator hose up and out of the way, I could HEAR the leak. It was a tear in the underside of this elbow. The tear was about an inch long!
The elbow is 5/8 inch in diameter, so I just went up and got an elbow meant for a heater hose and cut it to fit. The part number I used was Gates 28466. I saw someone on another forum with the same exact problem, so others with the dreaded codes would be wise to check out this elbow carefully.

Hope this helps,

Bob