PO171 & PO174 Code, With A Twist

Okay, I replace the complete upper intake (both halves) with new parts from Dorman. Replaced the front valve cover and associated parts as part of that kit. Replaced plugs and wires. Cleaned IAC & throttle body.

Reassembled everything and initially it ran great. Then I got a check engine light and it started to run like crap.

Got codes from Advance Auto Parts and found U1262, P0171, and P0174. Mind you I never had the P0171 & P0174 codes before all this. Developed a leak in the coolant tube under the intake and figured since it was all off, may as well replace it. The intake was soaked with oil as expected.

So now it runs terrible, goes through gas like water and I don't have a clue what to do next.

Thanks for any suggestions.

Jon

About the codes:

This group of codes indicate a condition that the indicated oxygen sensor is reporting.
These codes are almost NEVER caused by a defective oxygen sensor or sensor circuit.

P0171 Oxygen sensor reporting too lean condition on bank 1 (rear bank)
P0172 Oxygen sensor reporting too rich condition on bank 1

P0174 Oxygen sensor reporting too lean condition on bank 2 (front bank)
P0175 Oxygen sensor reporting too rich condition on bank 2

Lean codes almost always are a result of a vaccum leak (all years and engines).
1999 3.8L and newer windstars refer to sticky post on P0171 / P0174, this TSB does NOT apply to 1998 and older or 3.0L engine.
Lean codes can also be a result of clogged fuel injector(s) or fuel delivery issue.
Rich codes can be caused by a leaking fuel injector or misfire due to no spark to one or more cylinders
Lean and rich codes can be caused by MAF issues (try cleaning).

Here there is more info about it
http://leckemby.net/windstar/windstar01.html

U1262 is a communication bus failure which means the communications system between PCM, IDM, GEM fail to communicate with each other. Sounds like a connection may be loose in the harness. Is ABS light on?

Btw, please give year of your windstar.

About the codes:

This group of codes indicate a condition that the indicated oxygen sensor is reporting.
These codes are almost NEVER caused by a defective oxygen sensor or sensor circuit.

P0171 Oxygen sensor reporting too lean condition on bank 1 (rear bank)
P0172 Oxygen sensor reporting too rich condition on bank 1

P0174 Oxygen sensor reporting too lean condition on bank 2 (front bank)
P0175 Oxygen sensor reporting too rich condition on bank 2

Lean codes almost always are a result of a vaccum leak (all years and engines).
1999 3.8L and newer windstars refer to sticky post on P0171 / P0174, this TSB does NOT apply to 1998 and older or 3.0L engine.
Lean codes can also be a result of clogged fuel injector(s) or fuel delivery issue.
Rich codes can be caused by a leaking fuel injector or misfire due to no spark to one or more cylinders
Lean and rich codes can be caused by MAF issues (try cleaning).

Here there is more info about it
http://leckemby.net/windstar/windstar01.html

U1262 is a communication bus failure which means the communications system between PCM, IDM, GEM fail to communicate with each other. Sounds like a connection may be loose in the harness. Is ABS light on?

Btw, please give year of your windstar.


2000 Windstar SEL with 103,000 miles, and three transmissions so far. I did everything call out on the leckemby site already. That was this recent project.

No ABS light, I guess I have to check all of the electrical connectors that I did not remove/replace to see if perhaps I jarred one loose.

Thanks,
Jon

If it now runs "like crap" ... I'm betting on a massive air leak (did you put that hose back in place on the "rear" of the plastic piece of the manifold?) ... or the cables are not in the correct order ... or loose...(yes, this can cause those codes!).

Another thing to check would be the IMRC links....make sure to verify that BOTH IMR rods (1 in each bank of cylinders) in the lower intake manifold.
You were working very close to those when you had the upper intake off, and that is a common failure....the nylon links break / fall off.

Also triple check all the vaccum lines, any one of which could cause a vaccum leak and it is super easy to forget one, bump one off, or have one loose.....not to mention one being brittle and breaking.

Do a Smoke test to chase your vacuum leak down, see
http://www.youtube.com/watch?v=FfiQ7qWiG-M