wssix99

iTrader: (5)

You inherited a high-maintenance configuration, then. Before going any further, I would confirm your original traction control status via the RPO codes on the door, just in case. (Presumably, you don't have TCS because you would have run in to that during your rear end swap.)

I'd also figure out what is up with your ABS and if it was deleted previously.

Your tires aren't that far apart in circumference brand new. (2.6" delta) If they were close enough to not cause the ABS system fits originally, going with worn fronts and new rears could increase the differential just enough to start causing problems for you.

Pontiac428

Wish I knew more about the car...man that owned it passed away. It's been lowered, cat delete, LT headers, heads, cam and so on. Low miles too so suspension wise it's in good shape for the year.

Pontiac428

Car feels like the tires are really low on air...that's the best way I can describe it.

JD_AMG

What air pressure are you running in the tires front and rear? Go outside and check now, don't just assume.

Pontiac428

35 rear 35 front

JD_AMG

Lower it to 30psi front and rear and take a drive.

wssix99

iTrader: (5)

You probably should take the car to a speed shop, then, which deals in these kinds of modifications and can decypher the puzzle. Without a clear picture of what's on the car and what's been deleted, reprogrammed, tuned, etc. from the computers/systems, we'd just be playing whack-a-mole with this problem. (Particularly since you've had the car up and everything seems intact.)


There may be just a few simple things to try/explanations for your feel:

Your new tires on the rear will have more grip than balding tires. (I presume this is why you replaced them.) If so, they will feel like a "flatter" tire that would have more grip of the road, particularly with worn fronts that will slide around more than the new rears.

Pontiac428

Ok, tire pressure seemed to help some...still seems sloppy to me compared to the way it was before it went in the shop for new rear tires. The tires on the front look new but they are not. I believe by the date code on the tires they are 6 years old. As far as a speed shop goes for tuning I don't have a clue who I can take it to and trust them. I live in the Jacksonville FL area so I guess I will do some research.

flyboy129

If they are 6 years old, the rubber has hardened and deteriorated. ie: lost its ability to 'grip'.