Chevrolet Repair: 2000 chevy cavy stalling when stopping, chevy cavalier z24, 2000 chevy cavalier z24

Question
QUESTION: 2000 chevy cavalier z24 vin T manual. no operating problems at all except it dies 98% of the time i come to a stop. restarts immediately. If i barely even touch the gas right as i stop it doesnt die and idles normally. new plugs, new coil pack. any ideas?

ANSWER: HI DAN, TRY TO CLEAN THE [BACK SIDE OF THE THROTTLE BODY PLATE] WITH INJ CLEANER AND A SOFT BRUSH. REMOVE ALL THE CARBON BUILD UP THATS ON IT AND SEE IF THIS HELPS..ALSO MAKE SURE THERE IS NO DEBRIS IN THE AIR DUCT WORK LEADING TO THE THROTTLE BODY FROM THE AIR FILTER.. IF THIS DOES WORK,, YOU MAY NEED TO GET THIS ENGINE SCANNED AND CK THE DATA FOR A PROBLEM WITH THE [IAC]>>> IDLE AIR CONTROL MOTOR..YOU MAYBE ABLE TO CLEAN IT OUT OR YOU MAY NEED TO REPLACE IT... I HOPE THIS HELPS YOU,LET ME KNOW..TOM...

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QUESTION: So i pulled the iac and checked. it. It functioned normally, then i reinstalled it and started the vehicle and for no reason what so ever the issue with it dying at a stop went away. ran fine for 2 days and then developed a different problem. Now when i press the gas pedal it idles down and stays down for about 3 to five seconds. makes a puh..puh.puh.puh. then it catches up and revs maybe 500 rpms more than i wish. if i pump the gas it idles down while im pushing thenwhen i release the gas after pressing, it idles up to 1500 to 2000 rpms then drops back to idle. If i hold in the clutch and feather the gas i can catch it as it revs to 2000 and get the vehicle moving. at any time the rpms are below 1800 it could idle down when i press the gas even if already rolling or shifting gears. If i hold the gas pedal at a small amount of feed it will backfire  and die hard enough i have to push my map sensor vacuum line back on the (vacuum manifold?). occasionally while trying to maintain speed going down a hill the rpms will fluctuate bad enough to cause the car to shake back and forth.

Answer
HI DAN, THIS REALLY SOUNDS LIKE THIS CAR NEEDS TO BE SCANNED FOR LIVE DATA TO WATCH WHAT IS GOING ON..BUT I WILL TELL YOU THEY WAY YOU ARE DESCRIBING THIS IT SOUNDS LIKE A BAD MASS AIR FLOW SENSOR.  WHICH THIS DOES NOT HAVE !! SO IF WE ARE GOING TO GUESS AT THIS,IF IT WERE MINE I WOUOLD UNPLUG THE MAP SENSOR AND SEE IF THIS PROBLEM GETS BETTER. IF IT GETS BETTER I WOULD REPLACE THE MAP SENSOR..WHEN YOU DO THIS THE CK ENG LIGHT WILL COME ON OF COURSE, JUST IGNORE IT..KEEP IN MIND THE ENG WILL NOT BE 100 % BETTER  BUT IF THIS IS THE PROBLEM IT WILL BE BETTER. IF NO CHANGE CK FOR VOLTAGE REFERENCE ON ONE OF THE WIRES TO THE MAP SENSOR,I THINK 4.5 TO 5 VOLTS. THIS WAY WE WILL KNOW IF THE PCM IS WORKING OK..  LET ME KNOW HOW YOU MAKE OUT WITH THIS,,,,TOM..