This bog your experiencing is normal and can be cured with an aftermarket PCM ,you are getting TC lockup at low speed and its just like driving a standard in to high of gear and trying to hit the gas without downshifting,try this when you go to accelorate lift your foot off the gas just a little then step down it should shift you down a gear and provide smooth going .Chico.

Hi GRANDTOURING,
I noticed your profile listed these mods: Hypertech PowerStat Thermostats, Digital Horsepower PCM, Fenderwell Intake, 3.4
I'm just thinking that if you've already done these, and still have your stock downpipe, cat, and u-bend, that could be your problem...

x2, you car is probably knocking so bad that its slow!

You need to get that things scanned, then throw on an exhaust d/p and ubend delete, scan it again, and get it tuned! You'll be happy then! My first major mod was getting rid of that ubend.

x4 on the exhaust.

THIS IS EXTREAMLY LONG REPLY BUT REALLY DESPRITE FOR SOMEONE NICE TO HELP ME Thats exactly how i discribed it, no downshift. and i have already bought a dh pcm second hand but updated, but have not installed it yet, i had mentioned before i bough some parts from PFYC, a 3.4 pully and a 3.2 pully just to have maybe change in the future, im going with the 3.4 for now, gator back v-belt's, speedbuilt fenderwell intake, which is already installed, and a 180 degree thermostate. and im about to purchase the straight pipe to replace the u-bend, and some coolant, give er a nice coolant flush, i have already replaced fuel filter, and pump, ignition coil, two plug wires, and air intake. BUT!, i heard that if you add an air intake, new pcm, thermostate, and what ever else, that it could make my problem even worst, but then again what is the problem, could be 10 different things, i stayed up till 3am this morning doing research trying to figure out what it could be, but the symptoms i have listed a few possibilities, here they are,

TOURQE CONVERTER
SPARK PLUGS (ive already changed)
FUEL INJECTION SYSTEM ADJUSTMENT
FUEL FILTER (ive already changed)
FAULTY SPARK PLUG WIRES
INTAKE MANIFOLD AIR LEAK
VACUMM LEAK
DEFECTIVE/NOT FUNCTIONING RIGHT ECM
FAULTY COILS (could be did change one when i first bought it last fall, coil tower was rusted)
BRAKES BINDING (everytime i start the car and put it in gear and start moving there is always a quick rubbing sound in the front like when anti-locks activated the sound it makes it the same is this normal?)
TRANNY FLUID LEVEL INCORRECT (well in the tank its about an inch over the top line and stays there, so i think! and the dip stick is fine, smells fine, looks fine i replaced the tranny twice in my 97 gtp so i know what to look for and listen for so i dont think its my tranny, this is why i need to see if it is the TC cuz if it is then it will frig my tranny right?)
LOW OR UNEVEN CYLINDER COMPRESSION PRESSURE
CARBON IN COMBUSTION CHAMBERS
DAMAGED IGNITION COMPONENTS
THROTTLE VALVE (is what i thought it was from the start)
SHIFT LINKAGE
TRANSAKLE MOUNT
EXAUST LEAK/NOT SEALED

see now guys, this is what im talking about, now you see how crazy this is driving me, like im obsessed with this car, all my money is in this car, i know i said too much but i really really need help, i know what everything is that i metioned and how to fix it, but which one is it? if i can fix this problem my gp would be perfect. its getting worst everyday, cant take it to the dealer cuz they frig ya, anyways if someone out there really wants to help me with this, it is very important to me, and im adding my mods next week so i need answers, BADLY! ill even pay for help at this point, all ive evr wanted was my grand prix growing up and now i have my second but its just not working out for me. ok ill shut up now, im just looking for some help. Thanks for taking the time to read this who ever did.

Can you first post up a sig saying what exactly you have installed other than what you have. It is confusing. If you have mods, like a 3.4 on there, that create more power and don't have any exhaust work done to eleviate the extra boost, then that could be the problem. You could be experiencing the clogged cat also.

ive installed my speed built fenderwell intake and thats it so far

if anyone here is still willing to try and help me after that insane long message i left, LOL,you's must think im nuts, anyways, anyone get back to me ok,

grahamdavis@sympatico.ca

Try using your new PCM, it really does sound like something "normal" with stock GPs. Make sure you have a tank full of 91 or higher octane gas before you do though.

PCM will just make it worst, i might have a TC problem, and many many more possibilities, i dont want to add anything more before i find out what is wrong with my car, had to sell my last 97 gtp after 2 tranny replacements dont want to go through that again, i just posted a new chat topic for this problem only, come check it out if you are interested, if not thanks anyways for your opinion.

so what do people think i should do ... should i put in a new resonator or should i just take out the old one and put new pipe in there. maybe i could run 3"dp along with 3" pipe back to my y pipe... i just dont want the droan inside the car to be extreamly bad

With FM's I would go with a res. or a glasspack if not you'll have droan coming out the wazoo.Chico.

Keep the stock muffs and do all the rest.

i allready put the FM on i dont want to pay and switch them out... i might put in a 3" dp and 3" Res any ideas on how that would sound