1999 Pontiac Grand Am P0507 Idle Control System RPM Higher

1999 PONTIAC GRAND AM
210,000 MILES • 4 CYL • FWD • AUTOMATIC
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TROY0007
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1999 Pontiac Grand Am 2.4L SFI DOHC 4cyl
when i come to a complete stop the rpms drop for a split second and then the engine starts to shack/run ruff.and when i shut the car off it shut off ruff.

when i am driving between the speeds of 20 to 40mph my RPMs get jumpy only if i am not pushing the gas peddle

P0507 Idle Control System RPM Higher Than Expected
Mar 22, 2009 at 7:51 AM
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MMPRINCE4000
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Remove and clean the IAC (Idle Air Control valve) both base and pintle. They can get clogged up and not operate properly. If problem persists, remove and clean EGR valve, both base and pintle. EGR flow at idle will cause stalling, lower rpm and rough idleing. IAC


https://www.2carpros.com/forum/automotive_pictures/108325_GA_IAC_1.jpg

EGR


https://www.2carpros.com/forum/automotive_pictures/108325_GA_EGR_1.jpg

Mar 22, 2009 at 8:50 AM
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TROY0007
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my engine does not have an EGR valve(check at pontiac dealship) and my Idle Air Control valve is 4 days old(new) and i have been driving the car long enough to let the PCM reset the iac but i am still having problems with the idle.

Could it be that the TPS(Throttle Position Sensor) is bad?, or MAF sensor/o2 sensor
Mar 22, 2009 at 9:00 AM
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MMPRINCE4000
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Yes could be all three or one/two.

It is best to view sensor data on scanner in live data mode. View values of each sensor, it is much easier to isolate the problem rather than spending unnecessary money on parts.
Mar 23, 2009 at 6:25 AM