custom tuning?

came across an ad on craigslist and was wondering if it had any benefit.

If you have a modified 3800 Series 2 and want to get the most out of your mods. Or even if you have a stock one and want to gain 1/2 second in the quarter mile without installing a thing. Then get your car's pcm adjusted.
97-03 Grand Prix - All 3.8 Models - 97.5 - 03 Regal - All Models - Riviera's - Bonneville's ect.


Options:

Speed limiter removed
Raised rev limiter
Raised shift points
3-1 and 4-2 skip shifts
Programmed for added timing
Transmission line pressure increased
185F fan turn on
90 second fan on at key-off (this feature activates when engine coolant is 180 degrees or greater)
MAF calibration is year specific
WOT fueling richen to reduce KR
Removes lag by changing downshift tables
Correct VIN number programmed in (if put in note section)
Part throttle KR issue fixed
Torque abuse modes are modified to eliminate bog at launch
Shift KR is remapped for modified vehicles
Power enrichment tables modified for cars running increased boost
P0128 code removed for running drilled or 160 Tstats on newer cars
Torque converter lockup tables modified to improve transmission life and eliminate converter lockup hunting
Fiero PCMs have all codes deleted for use in the Fiero, 1.0 features, security disabled, ABS disabled, etc (use the year of your engine on the drop down and all 9's for a vin)
Sand rail PCMs have all transmission settings disabled, all codes deleted that need to be, security & ABS disabled (use the year of your engine on the drop down and all 9's for a vin)

$50.00 For a Base tune. $40.00 For Custom tunning per hour.


any advice would be great. Thanks!

It sounds like someone purchased a hand held tuner and is willing to utilize it on other cars for a price. The items he states in the ad are pretty standard for a tuner which changes the perimeters in the computer. The engine performance will benefit from such a tune and given the price it is not a bad deal but beware since each time you want to go back to the stock tune you will have to go back to the same guy to have the stock tune reinstalled in the PCM.

would doing the above, help with gas mileage and acceleration? what would be the significance of getting it back to stock tuned?

My cars basically all stock ( 97 grand prix gt, 143k) besides a cold air intake

You're not going to make a GT fast without top swapping it.

im not looking to really upgrade it max yet. just slow customizations and mostly want to see better performance and response with some gas mileage

The ECU tuning is mainly meant for GTP's that are already modded. Its not going to help much, if at all, with a GT.

A power tune will help with performance with any engine but it may decrease fuel mileage due to the increased fuel usage for more power. If the tuner is capable of a fuel economy tune it will help with mileage but given the perimeters you indicated I doubt that your fuel economy will improve.