[Bullitt512]

I installed Magnapack Axlebacks, disconnected negative side of battery before, and now "Low Tire Pressure" light came on, about 20 minutes into test drive... Anyway to resolve this without a tuner???

Definite change in HP... Sounds fabulous...

Thanks,
Jim

[PLstang]

Other then checking the tire pressure I don't think you'll have any problems.

Might just need to run a few cycles. Nothing you did should have affected the Tire Pressure sensors. Maybe with the colder weather you just need to add some air.

No need for a tune with AxleBacks.

[stlwagon]

Disconnecting the battery wasn't needed. Agree that you should check tire pressure.

[Bullitt512]

It turned out to be low air pressure... The car is only 6 months old and all tires were at 26lbs... I guess dis & reconnecting the battery reset something for the light to come on... Never came on before...

Anyway, thanks...

[travelers]

That why your recommend to check you tire pressure at least once a month. After you air the tires up you need to just drive the car a mile or so and it will reset.

[Bocephus357]

You have to be over 20mph for a few minutes (5 I think, but I'm not sure) for the TPMS to reset.
I got my mustang in june, and by mid October all of my tires were around 20psi.

[ski]

Originally Posted by Bullitt512

The car is only 6 months old and all tires were at 26lbs...

It's possible that your car's tires had the correct pressure when you first got it for the following reasons:

1- The ambient temperature may have been higher last May than it currently is in your area, which will lower the tire pressures by approx. 1 psi/10 F drop in ambient temperature.

2- All tires leak pressure over time.

[Smokievol]

Try Nitro Fill, The dealer supplies this with all new car purchases. It seems the tires never lose pressure. My second set of tires only loss a pound after about 6 months of non use.
Only read good things about Nitro.