Stalling when shifting into gear

[RedZMonte]

Ok so on top of the (P0172) code sometimes when i start the engine it will rev up then drop down low then rev up again and then smooth out but as soon as i put trans into gear (rev or any gear) the rpms drop and it dies. I have to rev up a little and put into gear, it still stumbles but i can nurse it back up.. once its in gear its fine.. idles and drives fine. It doesnt do it all the time its random when hot/cold.

Did '96 intake swap and repalced upper gasket, lower gaskets, Inj. O-rings, TB gasket, Plennum arm gasket, PCV, Valve cover gaskets...
* Checked for vac leaks (none)
* No changes to PCM
* IAC, TPS, MAP off Car from yard... (not throwing any codes)
* NGK G-Power plugs (Platinum) Gapped to ~.045

Im thinking it may be an MAF going bad or dirty... would that give me the symptoms im seeing along with the P0172 (System Too Rich Bank 1)?

only started happening after i did the '96 intake swap and related parts (listed above), any suggestions would be appreciated...

S

[robertisaar]

* No changes to PCM

that combined with a different intake could possibly do it if the IAC isn't commanded to open enough whereas the older intake may not have needed the extra steps...

or at least that's my opinion.

got a log of it happening?

EDIT: though the fueling rich error could point to the MAF being bad as well...

[Incydowt]

I experienced the same problem with my 3.4 Cutlass, I did the IAC, MAF, to no avail, turned out that I had a lazy O2 sensor that wasnt tripping a code, If you have access to a scan tool I would watch the O2 (upstream) for slow readings, I put that in the car was fine...

[pocket-rocket]

Luckily for him, Shane just got an HPT setup

[RedZMonte]

I did scale down my MAF a little ~10%, the car runs much better, seeing 11-11.5:1 under load, also idles a little better. Also cleaned maf with maf cleaner, didnt seem to change anything with the cleaning.. so it kinda looks to be a tune issue.

I might try another maf to see if it runs/idles any better just for curiosity.. might also get a new O2 just for grins.. she is getting old so it may be a combo of a few things..

Thanks for you help guys

S