2004 Grand Prix getting 7 to 13 mpg in city?? HELP PLEASE

[jessep28]

Reset the trip counter after filling up. Then when you get gas the next time, calculate the MPG by dividing the trip counter by the gallons pumped.

[cindyhh]

I am sorry, I know I am a woman and all, but I do have a college degree, and do know how to calculate many things more complex than mpg The quadratic equation is a little more complex, so I can handle this LOL. ALso, I don't have a computer on the GT to tell me, and even if I did I wouldn't believe it..
Any more to help?

Originally Posted by jessep28

Reset the trip counter after filling up. Then when you get gas the next time, calculate the MPG by dividing the trip counter by the gallons pumped.

[jessep28]

I never intended to insult your intellitgence.

I was just going off of the trip computer comment.

[04GTP-WhatLAG?]

here is a question, why the hell did they not include an oil pressure guage on the 04' gps?

I don't want to sound all ricer with aftermarket guage talk, but I'm seriously considering getting an aftermarket oil pressure guage...

How hard is one to wire and how would the warranty be effected? And if myself doing it would, does GM do this sort of thing?

*sorry to hijack topic just didn't feel like making another one*

[BNaylor]

Originally Posted by 04GTP-WhatLAG?

here is a question, why the hell did they not include an oil pressure guage on the 04' gps?

I don't want to sound all ricer with aftermarket guage talk, but I'm seriously considering getting an aftermarket oil pressure guage...

How hard is one to wire and how would the warranty be effected? And if myself doing it would, does GM do this sort of thing?

*sorry to hijack topic just didn't feel like making another one*

I suggest that you open a new topic and I'm quite sure a lot of us will weigh in to help out. Otherwise it will just be confusing. Plus it's way off the original topic.







Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.

[cindyhh]

no offense taken at all, It was just funny to me, i own 2 Dodge Demons and have rebuilt many motors, with a little help, so it was just funny. I can pic out everything for the 340 but when it comes to the newer stuff its a mess to figure out. Except for calculating gas mileage. Did anyone know how much and how many o2 sensors there are? Also, if it was making the mileage so bad why wouldnt it throw a code? I read on the cats, and i dont have any rotten smells, etc, so i dont think thats it.. any other ideas?
In anyones opinion, I would assume the tune up and plugs will only help marginally but i could be wrong, please correct me if so.. thanks

[BNaylor]

Originally Posted by cindyhh

no offense taken at all, It was just funny to me, i own 2 Dodge Demons and have rebuilt many motors, with a little help, so it was just funny. I can pic out everything for the 340 but when it comes to the newer stuff its a mess to figure out. Except for calculating gas mileage. Did anyone know how much and how many o2 sensors there are? Also, if it was making the mileage so bad why wouldnt it throw a code? I read on the cats, and i dont have any rotten smells, etc, so i dont think thats it.. any other ideas?
In anyones opinion, I would assume the tune up and plugs will only help marginally but i could be wrong, please correct me if so.. thanks

With all due respect, you have to start someplace which includes a basic tune-up (plugs, wires, fuel filter, air filter, pcv valve) if you want the problem resolved or at least get a handle on it. If you check GM's emissions and powertrain warranty on your car, any possible 02 sensor or CAT convertor problem should be covered under the emissions warranty. It's typically 80,000 miles or 8 years, whichever comes first. Since you have 75K miles on your car it will be expiring soon. Certain 2001 - 2002 Grand Prixs had their emissions warranties for CAT convertor extended to 120K miles but I'm not sure whether it applies to the '04 and up models. They were defective.

You're probably better off taking it back to a GM dealer and let them do further testing using a Tech II machine. They can test the CAT convertor for efficiency and whether the two 02 sensors are working properly. There is one 02 sensor before the CAT and one after. The 02 sensors can range from $60 to $125 in cost each.

BTW - You cannot use solely smell to determine if a CAT convertor is causing your problem. And as others mentioned, you may not get odb-ii DTC error codes or a SES/CEL light. Plus the dealer can run either an engine vacuum test or exhaust backpressure test in addition to the Tech II computer. Good luck!







Thrasher CAI, DHP v1.0 PCM, SLP Headers,
3.25 SC pulley, CAIT GMAF, 2.5 DP/Hi-Flow CAT,
u-bend delete, 160 TS, ZZP Stage 1 72mm TB,
TB spacer, MSD 8.5mm wires, Autolite 103,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials
1/4 ET: 13.210 sec. @ 104.490 mph
0 - 60 ft: 1.945 sec.