mcypert

Hi all... 1999 base model was throwing codes 0410 &1411. Search here told me it was the electrically operated vacuum valve, the vacuum operated valve or the check valve.... All inconveniently located behind the alternator... I got all three before tackling the job.... Thanks to the folks here who posted on replacing these parts.... Back in 2009...

The easiest part to test is the check valve, but it's also the hardest to remove. Just blow through it. That's what was wrong with mine at 91K miles... the check valve... I replaced all three valves anyway, while I was in there.

(Here's a hint: one thread says to remove the Throttle Body. I did but found it unnecessary. Just take off the serpentine belt and other stuff to get the alternator out... Turn alternator counter-clockwise and tilt back... You can pull it out far enough to take off the two alt wires, but DO discon the battery, for sure. The three valves are back there and you can get at them... I used a 10" pipe wrench to take off the check valve...avoiding having to buy and modify some 27mm claw tool.... I installed/tightened the check valve with channel locks...)

And, a little more info.... with a bad check valve, you can clear 0410 & 1411 and drive for one day. I even passed Texas emissions that way... But the next day, on a cold start, fault codes and CEL will return...

So, on my first start with a new check valve, I got no CEL...Also, IIRC, with the bad check, the cold-start air pump will run for a minute or two, go off, and then come on again for a brief time... With the new parts the pump only ran once... telling me the problem was sorted... NO????

Finally, HERE IS MY QUESTION....

Next day, second cold start, with the new parts, I get code 0444. not 0410 or 1411....

O444 has something to do tank venting and a purge valve, But I'm asking myself, "Self, what did you not get back on right????"

I also remember telling myself when installing the new parts, "Self, you make damn sure you have all the hoses and connection on right, because you don't wanna have to pull all this crap off again to check them." And, I did, make damn sure everything was right that is...

I cleared 0444 and restarted. No codes, but that's a hot-start... Will I get 0444 on the next cold start?

So, did I do something to trigger 0444 or is it just a coincidence????

One more bit of info... Searching here, I found 0444 may be related to the gas cap or fuel-tank pressure... I took off the gas cap after getting 0444 and pressure was quite high.... Took several seconds for pressure to equalize... Could that be all it was???

I'll know more on the next cold-start, but I'm selling the car (don't want too, but relocating and must).....I won't sell if anything is wrong with car, so I want to make sure if I say it's fixed, It's Fixed...

Any advice, comments appreciated.... Thanks Mark