171-174 codes after tsb

Hey All
I have a 2000 3.8 windstar with the dreded code's. Two years ago the dealership replaced the isolator bolts & the Valve cover & it stayed off long enough to get a inspection sticker.About three days. Now two years later I did the tsb again ( bolts, gaskets - upper & lower, & throttle body, Vacume line to valve cover).Cleaned the MAF. The light stayed off for about 120 miles. I had been checking my code reader as miles went by & never made it though all the system cecks. All systems made it but ES- evap sytem. I don't know if that offers any clues to any body. All vac lines & elbows fittings seem fine. The van runs better than it has but still has codes.

Thanks Ed:banghead:

Something was missed. I have been code-free for some 140 kmiles plus.

Did you do the job yourself the second time around? Make sure the bellows between throttle body and air filter is seated properly on both ends and has no splits. Is the vacuum tube in place on the back side of bellows/rear (RH) valve cover?

Which codes do you currently have?

Hi Ed,

You might very carefully check the vacuum lines to the Evap solenoid on the firewall - I think you will have two vacuum sources to it. You might find a leaker along there somewhere. I would think that much of a leak would produce a rough idle, but maybe the evap codes are a clue. Clearly the PCM thinks things are a bit lean so air must be sneaking in somewhere.

Good Luck

Something was missed. I have been code-free for some 140 kmiles plus.

Did you do the job yourself the second time around? Make sure the bellows between throttle body and air filter is seated properly on both ends and has no splits. Is the vacuum tube in place on the back side of bellows/rear (RH) valve cover?

Which codes do you currently have?

yes i did the work myself second time & have somewhat of a mechanical past with autos, I will check the bellows.
The codes are still just 171-174
thanks for the ideas

Hi Ed,

You might very carefully check the vacuum lines to the Evap solenoid on the firewall - I think you will have two vacuum sources to it. You might find a leaker along there somewhere. I would think that much of a leak would produce a rough idle, but maybe the evap codes are a clue. Clearly the PCM thinks things are a bit lean so air must be sneaking in somewhere.

Good Luck

I agree on the idle with those lines, I will check again, but like i had said the van runs smooth.
thanks for the thought

e

yes i did the work myself second time & have somewhat of a mechanical past with autos, I will check the bellows.
The codes are still just 171-174
thanks for the ideas

& the rear valve cover vac line is installed.

& the rear valve cover vac line is installed.

After further inspection found a crack in the upper intake,
Orderd new one, should take care of it, I hope

Ed