Question about 2000 Pontiac Grand Prix

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2000 grand prix 3.8L code comes up as evap. system what could it be?

I have a 2000 grand prix with the 3.8L, 185,000 miles. It runs great when you drive it for the first time a day but when you shut it off and restart it most of the time the rpm's will bounce. Also when you drive down the road it keeps acting like it going to die and sometimes does at stop lights. I put a scanner on it it comes up as the evap. system. What do i need to change to fix this?

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  • jh21crew Oct 10, 2008

    Hmm well that is the only code that comes up. The check engine light does not even come on. Im pretty good with cars but just cant figure this one out and its driving me nuts. Lets say when your driving the rpm's are at 2000 it feels like it wants to die for just one second and it drops 500 rpm's then kicks back up to 2000 even on cruise. A guy from work said it might be the crank censer but im not about to spend the money if im not sure it will fix it. Maybe its time i get off the wallet and bring the car into the shop. Thanks

  • jh21crew Oct 22, 2008

    I unplugged the maf sensor and it quit doing it so i replaced it also works like a charm. Thank you very much. Big help....

  • chillywhilly Jan 20, 2009

    I have a 2000 Grand Prix GT. It seems like sometimes that it does not wasnt to shift into it's over drive gear, it does but acts like it does not want to. Then when you are just sitting at a light or something it almost feels like someone one bumps the back of my car then I notice that the RPM's go very low and then go back to normal. Any idea's?

  • yadayada
    yadayada May 11, 2010

    The evap system will not cause these kinds of problems you listed, the code was most likely caused by a loose gas cap.

  • Anonymous Mar 30, 2014

    where is the evap system



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I had this problem and I replaced the mass air flow sensor and it runs great, was told by my mechanic it is a hard problem to diagnose. I just unplugged the maf sensor and the car ran better so i replaced it.

Posted on Oct 21, 2008


The blower motor first started cutting off for a few seconds and then back on. When the blower would cut off so would the rear window defogger and air conditioning light as well as the headlights if the headlights were running on automatic. If the headlights were manually turned on they would not turn off. You can hear what sounds like a relay clicking when it cuts off. Replaced the battery but had no effect, can't find the problem. The problem was intermittent for a while where it would cut off for 10 - 15 seconds and back on. The problem has progressed to where on blower speeds 1 - 4 will not work at all, when you place it on any of those speeds, rear window defogger will cut off as well as the running lights and of course, no air will blow. Speed position 5 on the blower works as well as all electrical while on that speed. The key is the blower speed, it's like something is shorting or not grounded causing perhaps a protection circuit to cut power?

Posted on Oct 22, 2008


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2008 Pontiac Grand Prix blowing the MAF/EVAP fuse. Unplugged MAF and still blows fuse. Let vehicle sit and cool and it didn't blow it again. Plugged MAF in, cleared codes and drove @ 15 miles and it blew...

Replace the EVAP purge solenoid. It is powered off the same fuse and it works as you are driving and not at idle . The MAF sensor is working all the time the engine is running.

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Dec 02, 2013 | 2000 Pontiac Grand Prix

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My 2001 grad prix stumbels at acceleration once in awhile and in park sometimes there is no engine codes and i've changed pretty much everything plugs wires coils fuel filter and i even cleaned th

You did oxygen sensors at 100,000 miles

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No intake or evap leaks

Changing parts doesn't answer the question
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Mar 13, 2013 | 2000 Pontiac Grand Prix

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Check gas cap

You'll need to get the computer scanned for trouble codes.
Chances are there is a small leak in the EVAP system. Could be a valve or hose in addition to the gas cap.

Feb 28, 2013 | 2001 Pontiac Grand Prix

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2000 Grand Prix EVAP System

If you have access to a 'smoke test machine' this will enable you to detect and locate the leak. If UV sensitive dye is also in the oil that creates the smoke for the smoke test, you can trace it with the UV light that comes with the machine.

Jul 27, 2012 | 2000 Pontiac Grand Prix

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How do you repair P0446 trouble code on a 2000 pontiac grand prix gtp?

P0446 - Evaporative Emmission Control System Vent Control Circuit
Evap vent valve has only one purpose. It closes in order to seal the vent so the EVAP system can pressurize and ensure there are no leaks. Evap vent valve is usually supplied Batt. voltage with key on. The ECM's driver controls the ground, and when grounded, activates the valve (closing it). If the ECM detects a short to ground, and open,or a short to battery voltage on the control circuit, P0446 will set. Code also may refer to ECM detecting that EVAP system is unable to achieve or maintain vacuum during test.

Symptoms: There will be no obvious symptoms to driver, other than MIL illumination.

Causes: A code P0446 could mean one or more of the following has happened:
* Faulty vent valve
* Open, short or excessive resistance on Vent valve control circuit
* Blockage of vent valve
* Bad PCM

Possible Solutions: With a P0446 OBD-II trouble code, here are some things to try:
* Replace Vent valve
* Repair open, short, or resistance problem in control circuit
* Repair open, or short, or resistance problem in power circuit
* Replace PCM

Review this information, Test it and tell us news.

Feb 15, 2011 | 2000 Pontiac Grand Prix

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1999 grand prix code P0108 and P0141

Until the problem is repaired the codes will come on

Jul 06, 2010 | 1999 Pontiac Grand Prix

1 Answer


The evap system may be located right next to the fuel tank. You'll most likely see a can, hoses, solenoids, etc.

I hope this points you in the right direction! :)

Jan 06, 2010 | 2000 Pontiac Grand Prix

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