Hey guys, long story short version:

2002 f-150, 4.2L v-6, 5 speed.

for a year now the SES light has been on.
Started out with both banks lean, now only bank 1 lean (again).
I'm not able to provide the specific codes at this time.
I'm a certified tech so I feel kinda stupid by this point.

Multiple scans, Multiples parts thrown it's way:

3 DPFE sensors
EGR Valve
3 MAF's
2 complete sets of O2 sensors (2 each bank)
Plenum spacer with updated isolator bolts (twice)
New plugs (wires were good at the time)
Of course new air filter (on regular basis), new fuel filter(s), oil changes every 3k, Trans and differential serviced regularly.

Fuel injectors test fine, no noticeable running problems (sometimes a little bit rough at first start up for about 2 minutes).
Have checked for vac leaks throughout (smoke machine, and the old reliable carb cleaner near possible leak locations).

It's also had a couple sea foam "treatments".
AND: it makes no difference how many times I reset the code(s), they keep coming back.
I'm ready to drive this thing in to the lake.
have NOT replaced the cats, coil, plug wires or fuel injectors.

Any ideas or suggestions would be appreciated, I have to get this thing inspected next month and the light cannot be on (or reset within 2 cycles).

 

If codes are setting off the light, then you need to resolve the issue to clear the code and the light will go off.
If you can't tell me what code it being thrown then I can not tell you how to solve the problem and clear the code/turn off ses light.
Why do you keep throwing the same parts at it.

Codes..........Need the codes

What kind of tech are you????

 

As I said, the codes thrown are for lean condition, bank 1, I'm not sure the actual codes at this time, and what do you mean by "what kind of tech are you".....I'm a certified auto tech (everything but automatic transmissions) and I've also had Ford specific training.

As for throwing the same parts at it, they were under warranty from the parts dealer, most of which tested bad...for example I did get a faulty MAF the first time around, and the plenum spacer did in fact warp AGAIN.

 

if you keep getting lean codes and changing O2 sensors don't fix it, i would look closely at the cats.

 

There could be a few reasons for the lean condition, but you already know that. Codes will go along way to helping you solve your problem.
Did you replace those parts to try and solve the problem or are they just parts that have been changed?
As for the parts themselves, If you need to replace every part two or three times, because of faulty parts......you need to find a need parts dealer.


I noticed in your first post, that you stated that no matter how many times you reset the light, it keeps coming back. That is why I asked what kind of tech you are.

 

You may be right, but if I were him, I think I'd try an o2 sensor from a different supplier first. I'm not sure where he gets his parts, but If got that many bad parts, you can bet I'd be moving on. It also makes it hard to solve a problem if you're not sure you can trust the parts you're putting on.

 

If you have not already done so, I would suggest using "Search" to search the 4.2 forum for "lean" and the specific code(s) when you get them.

There is a lot of history here and the answer might be sitting in an old thread just waiting for you to find it.
(example: I remember the little rubber elbow going to the PCV valve was bad to fail and cause lean codes)

Best of luck!

 

If you scans read "lean on both banks", i bet you have a vacuum leak. Had the same problem in a ranger of ours. Both banks said lean, talked to a guy at advaned, when he scanned the codes, he suggested that, and after 2 min of checking the vacuum lines, a line had come loose from i dont know what it is, but it cleared the codes. You might try that.

 

Sorry if I sounded a bit defensive, I understand where you were coming from. I don't just clear the codes and hope for the best...there's alot more diags than reading the codes...BTW code P0171 As for the parts, I started going with only Ford parts since I was having such a problem, a little bit more money, but much more reliable...since I started putting only original equipment on it, the new parts test fine, I guess I should have been a bit more clear.

 

I appreciate all the input in this thread. I am reading and considering every last bit of helpful information...thank all you guys for the comments so far.

 

No worries.......
Have you thoroughly checked all vacuum lines? Check all the known trouble spots.

 

I'm double checking the vacuum lines this afternoon...I looked at the little "problem" elbow this morning and did notice that it's very soft and feels like it could come apart in my hands, so I'm replacing that just for good measure...wouldn't that be a cheap fix

 

Hope for the best! You might get lucky.

Oh and a FWIW... I have been hanging out here for 10 years. This thread is an example (to me at least) of some of what is the best about FTE.
A few feathers get ruffled - maybe just a little bit - and good guys make things right and then go about trying to help get a problem fixed.
Good job fellas!

 

well, everbody knows ya can't fly till ya get yer feather ruffled a little bit!!

 

as as their only ruffled, not plucked or cut