Engine Hesitation after quick stop

I have a 91 Buick Park Avenue with 140,000 miles on it. I recently had the Mass Air Flow Sensor changed because it went out. Before I had it done, before coming to a complete stop, the rpm would jump a little bit then fall below 1000rpm. After I got the sensor replaced it hasen't done it in a while but the other day I felt the hesisation in the engine after coming to a quick complete stop. Is the MAF sensor no good or is it another problem???

Sorry, but this could be any number of problems, the MAF, EGR, IAC, TPS, PCV, vacuum leaks, fuel pressure, or clogged fuel filter, just to name a few. You need to see if you have any stored DTC's first. Are you familiar with how to retrieve codes, using the "paper clip" method?

No I am not, can you inform me? :confused:

Locate the ALDL (Assembly Line Diagnostic Lead). It is located under the driver's side dash. Insert paper clip between terminals A & B as shown below.

http://img178.imageshack.us/img178/3331/obdikx3.jpg


Turn key on, but do not start engine. The check engine light will begin to flash. The ECM (computer) will display a "code 12" by flashing the "service engine soon" light, indicating that the system is operating. A code 12 is simply one flash, followed by a brief pause, then two flashes in quick succession. This code will be flashed 3-times. If no other codes are stored, code 12 will flash until the diagnostic terminal ground is removed. After code 12 has flashed 3-times, the ECM will display any stored trouble codes. Each code will be flashed 3-times, then code 12 will be flashed again, indicating that the display of any stored trouble codes has been completed.