99' check engine light on

[rangerone766]

000001999 buick regal ls 3.8 non-sc
about a month or 2 ago the check engine light started coming on intermittently. about 2 weeks ago it came on and stayed on.

i had the code read at autozone. they gave me a little printout, but the code is not on the printout-lol! here is the definition of the trouble code

MAP (Man. Absolute Pressure) BARO or MAF (Mass Air Flow) /VAF (Vane Air Flow) sensor condition.
Probable Causes:
1. Vacuum hose off, cracked or passage blocked-Engine mechanical timing condition.
2. Throttle body intake tube loose, off, or cracked
3. Barometer/MAP (Man. Absolute Pressure) defective
4. MAF (Mass Air Flow) /VAF (Vane Air Flow) sensor dirty or defective

i also must say. the car has been running fine. 100% ok in all re guards except i feel as the mpg has gotten a little worse since the light came on.

once i got the printout, i checked a few things.

vacuum lines all appear intact

airfilter is new and ducting intact

MAP sensor- still sealing the pcv valve in. so 0 vacuum leak there, but.. broken in 2 pieces diaphragm part connected to housing plug end of the part was dangling against the intake.

MAF i dont have the proper tool to remove it. but i did spray some MAF cleaner through the honeycomb.

order of events
had code read, got printout, went home

after car cooled off, went out to look it over

found dirty air filter

removed intake hose and sprayed MAF cleaner through honeycomb

drove to autozone, car ran fine, light still on

put new MAP sensor, pcv valve, and airfilter in left for home

2 miles away car sputters at take off, give it a bit more gas pedal. car takes off like a demon

pulled over thinking i installed parts wrong, pulled MAP and pcv valve. re-installed everything. 100% positive it is00 in there right.

drove home, car still running like dirt at takeoff sometimes.

could the new MAP sensor be bad? i think i'll put the old broken one in and see how it runs.

[rangerone766]

update-

super glued old MAP back together and put it on the car. car ran fine, engine light still on.

went to autozone and swapped out the sensor. put the new one on, car runs fine. 2 miles down the road engine light goes off.

[BNaylor]

Do you still have the original UIM and LIM gaskets? Common cause of MAP sensor issues. Hopefully just the MAP sensor was bad.

[richtazz]

Sounds like the MAP was the issue all along. That's why I stick with OEM branded emissions parts, the aftermarket stuff is too troublesome.

Just a note, when you swapped the PCV, did you remember to take the black o-ring off the old one and swap it to the new one? If not, the resultant vacuum leak can cause a lot of strange unrelated trouble codes as well as an irritating squeal noise.

[rangerone766]

Originally Posted by richtazz

Sounds like the MAP was the issue all along. That's why I stick with OEM branded emissions parts, the aftermarket stuff is too troublesome.

Just a note, when you swapped the PCV, did you remember to take the black o-ring off the old one and swap it to the new one? If not, the resultant vacuum leak can cause a lot of strange unrelated trouble codes as well as an irritating squeal noise.

car is running bad again.

no i didnt see a black o-ring, but there was a red oring that i re used.

also the dipstick is not sealing into the dip stick tube. i'm on the was to the junk yard nor for a new dipstick.

[rangerone766]

try this again. lol

got a new dipstick and snagged a MAF at the junkyard. the MAF i grabbed has a different part number the one i took off ended in a 4 the one i put on ended in a 5. the exterior housing is the same bet the sensor part that sits in the air stream is different.

the moment i put the MAF in the car started to run better. after 20 miles driving the check engine light turned off. its like a new car again, more power than i remember this regal having.

update- car is still running good.