Question about 2000 Pontiac Grand Prix

1 Answer

Changed Mass Air Flow sensor, CEL still displays problem

I have a 2000 Pontiac GTP (sc), 6 months ago, car stopped in the middle of the freeway for no apparent reason. Mechanic friend messed with car for awhile and as a last resort unplugged my Mass Airflow Sensor. As soon as this unit was unplugged, car ran perfect (even got better gas mileage oddly enough) Recently the CEL came on. CEL code stated I had a bad Mass Airflow sensor. Changed sensor, plugged it in... car wouldnt start! JOY!. However, car will run without the unit unplugged perfectly fine.

On top of this, the car has now started this wonderful ''shaking'' only when the car is in drive. Every once in awhile, when i release my foot off the gas pedal the RPM gauge will also randomly shoot from 1000 to 4000 and rock back and forth shaking the car while it does this until i place my foot back on the gas pedal again...

Any ideas?

Posted by on

  • 3 more comments 
  • tru2lyfe_4u Mar 11, 2009

    Tried that, no help for either problem. As far as the MAF is concerned, I'm at a loss. Tried testing the wires, voltage, etc, can't seem to figure out why the car will not run with that device plugged in (with the new or the old MAF sensor)

    Also, the shaking in the car, do you think it could be a possible exhaust leak that could cause this?

  • tru2lyfe_4u Mar 12, 2009

    I'll check the exhaust, wouldn't hurt, appreciate the help, let me know if you think of anything else in regards to the MAF... I'm still stumped on that one

  • tru2lyfe_4u Mar 16, 2009

    The test read a bad MAF. However, both O2 sensors were changed less than 6 months ago cause my CEL had come on then and read bad O2 sensors, both were changed at that time, CEL went off, everything seemed fine. I also had the catalytic converter changed roughly a year ago as well but I will take a look to see if this might be part of the problem just for GP.

    I had a friend of mine tell me to watch out for the k&n filter that I have installed. He also said that sometimes having it cleaned, if done wrong, can affect the MAF. However, if this was the case, would installing 2 separate MAF 5 months after the unit had been cleaned (and showed no problems that I am aware of) cause those 2 sensors to BOTH not work? I thought it was highly doubtful, but noted it none the less when he mentioned it.

    “water in the fuel injectors” – Hadn’t thought of this one yet

  • josh1111 May 11, 2010

    not really an exhaust leak it would be the same whenever the car is runnung, you could check it out though just crawl under and shake everything. ill think about this problem some more for ya

  • josh1111 May 11, 2010

    just an idea disconnect the battery and hook it back up.



1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Expert
  • 398 Answers

It almost sounds like a fouled fuel injector. this is a tricky problem because it involve so many different operations. the maf is used to deliver fuel and the o2 sensor tells how much. there are 2 o2 sensors one before cat 1 after. mabey check these out visually. the computer should pick these sensors up if there bad. is this a supercharged engine? ill try to come up with some other ideas for you soon.

Posted on Mar 12, 2009

  • 3 more comments 
  • josh1111 Mar 12, 2009

    exhaust leak is possible but it would have to be before o2 sensor.

  • josh1111 Mar 12, 2009

    water in the fuel injectors

    leaking fuel pressure regulator can raise the fuel pressure, causing a rich mixture condition.

    intermittent TP sensor output could cause the system to go rich due to a false indication of the engine accelerating.

    so fuel injectors or o2 sensors would be my next culprits

    did the cel test say bad maf or was it rich lean mixture problem?

  • josh1111 Mar 13, 2009

    did you do a computer test on this?

  • josh1111 Mar 13, 2009

    check the catylitic converter and 02 sensors. some people suspect also that k&n oil filters can screw up maf.

    also coils could be involved since it shakes and has a loss of power. good luck i feel you on this one$$$

  • josh1111 Mar 16, 2009

    also check the diverter/bypass valve.



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

1998 Pontiac Grand Prix GTP Starts and turns off approx 5-10 seconds after starting.

I would replace the TPS sensor. If you have fuel pressure enough to start the car, then you probably have pressure always. Before turning the key to start, turn to ON. You should hear the fuel pump pressurizing the lines. Turn the car back off. Go under the hood and remove the cap to the Schrader Valve. Use a rag to catch any fuel when you depress the valve stem. If fuel comes out into your rag, you should have pressure. Try this a second time to be sure. I had this issue with my car shutting down. TPS sensor replacement fixed it. could be vacuum lines, or another sensor fault. The TPS is a common issue. You may also want to clean your Mass Air Flow sensor with the proper solvent and technique.

Apr 10, 2014 | 2000 Pontiac Grand Prix GTP

1 Answer

Where is the mass air flow sensor on 2000 pontiac bonneville 3800 sle

mass air flow sensor is located on the air hose that leads to the air filter if you have the part just look for the same look to make sure.

May 15, 2010 | 2000 Pontiac Bonneville

2 Answers

Location of mass air flow sensor, 2000 Grand Prix GTP

The mass air flow sensor is a round sensor that is mounted in the air intake, between the air cleaner box and the engine throttle body.

Feb 07, 2010 | 2000 Pontiac Grand Prix

1 Answer

How do i replace mass air flow sensor on a 1999 grand prix gtp

u don't replace the whole sensor just the actual heated wire part, that is held in place by two star screws, see picture.
A-1 CARDONE Part # 7450015 {[Mass Airflow Sensor] Reman.} $142.00


Jan 29, 2010 | Pontiac Grand Prix Cars & Trucks

1 Answer

Were is the air sensor located on 2000 Pontiac v-6

I take it you mean the Mass air flow sensor. It's in the rubber flex tube that comes from your air filter to your intake.

Jun 02, 2009 | 2000 Pontiac Grand Am GT

2 Answers


Sounds like the coolant temp sensor has a problem. Check the wiring first then try a sensor. They are relatively cheap.

Nov 25, 2008 | 2000 GMC Sierra

1 Answer


Well there are several things that could cause this problem...

1. one of the coils may not be firing.
2. the ignition module could be bad.
3. the mass air flow sensor could be tellign the car to run rich (too much gas)
4. if the car is equiped with a map sensor it could do the same as a mass air flow sensor.
5. fuel pressure regulator could be leaking at vacuum port drawing in more fuel than needed.
6. the computer itself could be bad as well.

The car either has a map sensor or mass air flow not both. The mass air flow would be right after the air cleaner housing usually a 4 wire connector. map sensor is normally located on the rear of the upper intake manifold with 1 vacuum line going to it with 3 wire connector. Hope this helps.

Sep 11, 2008 | 1991 Pontiac Grand Prix

Not finding what you are looking for?
2000 Pontiac Grand Prix Logo

462 people viewed this question

Ask a Question

Usually answered in minutes!

Top Pontiac Experts


Level 3 Expert

78267 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Jeffrey Turcotte
Jeffrey Turcotte

Level 3 Expert

8836 Answers

Are you a Pontiac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides