Hey everyone. First of all, this car is a 2002 M/C SS. Over 150,000 miles. When the car is sitting at idle, the rpms will go from 800 to 1400 back down to 800. The rpm's will stick sometimes when I let off of the gas pedel and the car will accelerate itself up to 50 mph. When I get to my house, I will shift the transmission from Drive to Neutral, RPM's go up to 2400. From Neutral to Reverse back down to 1400. Reverse to park 2400 rpm's.

The car has a lot of problems that Im trying do address. Recieved a DTC P0446. EVAP system purge solenoid bad, or vent valve bad. But I dont think that this could be causing this.

Also got a DTC p0102. If I remember right this is a MAF Sensor gone bad.

My logic is telling me that It is a vacuum leak somewhere but ive checked every where and found nothing. The car doesnt stall out when I come to a stop so I dont think that it is the TPS.

Also the BCM is going out because the SECURITY light is on and I hear ticking in the dash while the headlights shut on and off.

My primary problem is the RPM spikes that I am getting. Any help or consideration would be very much appreciated. Thanks.

 

 

Attack the problem systematically. Get the codes read to ensure you know what the computer thinks is wrong. That will at least give you a starting point.

 

I already have. P0446 - EVAP purge solenoid and a P0102 - MAF Sensor

 

Could be a bad IAC. They sometimes stick wide open.
A purge valve stuck open will also cause a vacuum leak since you vent is always open unless the car is testing the evap system, but I don't think it would be enough to raise the idle that much, but its something to look into.

 

Check all of your vaccum lines also. If you're getting a MAF code, that very well could be the problem (leaking vac line).
Great time to invest in a vac gauge http://www.glowshiftdirect.com/white...uum-gauge.aspx
They have a store on ebay with way cheaper prices. I think like 25 bucks with free shipping for the light gray face 7 color.