Poor gas mileage in 2001 Grand Prix
 

Getting louzy gas mileage on Pontiac 2001 Grand Prix

Alright??? Are you looking for help as to diagnose why? we need more info to be of any help at all
HAs it happend all of the sudden
or was is gradual?
any SES lights? stuff like that

Threads Merged due to being same thng in two deiffrent sections!

Spoke with danthurs on 3/25, got a tune up but no luck. Spoke of PCM

so where do I go now??

What exactly did you and Dan discuss....What was done in your tune up? I.E. What parts were replaced???

Had a mechanic look at the car, said plugs were fine @ 92,000 miles. Checked O2 sensor said it was clean. Checked PCM said it was not bad. Dan mentioned that the PCM should be recalabrated.

Getting 10 miles per gallon in winter

winter blend fuels do no good for mpg anyways but wouldnt kill it that bad..Were the spark plugs and or air filter replaced? pcv valve how is tire pressure...Was the catalytic convertor checked?

I then talked to a GM dealer. He said tha if the PCM is bad a light woulld go on on the dashboard.Could this PCM be adjusted?

Were the spark plugs and or air filter replaced?No said they were in good shape

pcv valve how is tire pressure..do not know about pcv valve tire pressure good


.Was the catalytic convertor checked? I believe he checked that just had it inspected

Could it be that the PCM needs to be adjusted

Should get 18 miles per gallon even in winter??Most I ever got in 3 years of driving was 21

so did you give up with your posts or just too busy

Sorry i ran to the Hospital to try and get some relief for this upper respitory infection that hit me like a truck..It could possibly be the PCM But i would like to rule out simple cheap issues first!

I spoke with danthurs back on 3/25. He sent me an email yesterday explaining this:Ya, I still pop in here from time to time, I'm mostly on www.gmforum.com under the same name
Should speak with him??

Gas mileage poor
 

I have a 2001 Pontiac Grand Prix getting 10 miles per gallon in the winter. Just had the car tuned up and the mechanic found the plugs ok, changed the fuel filter and checked the O2 sensor. Nothing else to change?? What else could I be looking for??Mechanic also checked the PCM and said it was fine.

Should I be talking with danthurs

I have a 2001 Pontiac Grand Prix getting 10 miles per gallon in the winter. Just had the car tuned up and the mechanic found the plugs ok, changed the fuel filter and checked the O2 sensor. Nothing else to change?? What else could I be looking for??Mechanic also checked the PCM and said it was fine.

Should I be talking with danthurs??

No answers yet??

An engine running with fuel mileage that bad should be exhibiting other problems. What else can you tell us about other problems you are experiencing?

You didn't mention air filter. Has that been changed?

Do you have a lockable gas cap?

Tell us more.

What else can you tell us about other problems you are experiencing?Car runs fine, would not believe that it needed anything

You didn't mention air filter. Has that been changed?It was checked when I had the car inspected 1 month ago

Do you have a lockable gas cap?no

Tell us more.
This is a 2001 grand prix with a 3.8 engine. Best gas mileage ever gotten was about 18, in winter getting 10
Spoke with (emailed) danthurs said have the PCM checked. Mechanic checked this and said it was ok.
Then I called a Pontiac dealership and ask him if he would check the PCM.
He told me that if it wasn't working that a light would show up on the dashboard.
According to dan, he could have run a computer check up on this and maybe adjust, but the dealership said no

Someone at your place told me to check the PCV valve but I believe that the mechanic would have checked this upon inspection

Perhaps if you gave me your phone number I could call you and eliminate all these emails??

so what do you think??

can the pcm be checked or is it simply ok and does not need to be readjusted??

Check for any fuel leaks around the filter, fuel line, injectors, etc.

there are no leaks I would have noticed them in the drive way. What about the PCM

can the pcm be checked or is it simply ok and does not need to be readjusted??

moved to it's proper Mechanical Section. General Chat is for items that affect all platforms and "General Chat". It really helps the GearHeads, others with ownership of same/similar Models, the Forum regarding search bots, and our own internal search engine when we keep things in order. Thanx.