2003gtowner

If the back sensors are disabled, how do I turn them back on?

mustangted

the "tune" you have turned them off? If so you need an emission compliant "tune"

Jackharrisonswift

Ok, I have an 03 Mustang GT and I live in Texas and bought the car from California.
I was informed the car has the California Emissions control on it (because the previous owner lived in CA and had to have it on the car).

Can somebody explain what the emissions control is, and how it affects performance?
Can it be taken off because I live in Texas which does not demand the emissions control?.

cliffyk

The 2003 GTs were "50-state" vehicles, I.e. there was no California specific model.

Here's a link to Ford's OBD Summary for the 2003 MY, it describes the various emissions related systems. There's not much to be gained by disabling/deleting any of them.

My general recommendation for initial modifications are to open up the exhaust with 1-1/2" ID components from the exhaust manifolds back¹, then buy a tuning system and load a tune optimised for premium fuel (the stock tune is very poor with "safe under any possible condition" ignition timing and fueling at WOT). Next change the rear-end gears, the stock gears are 3.27:1 popular replacement ratios are 3.73:1 and 4.10:1--the tuning system will let you correct the speedometer for the new gears.

After that there are a number of popular modifications, search around this forum and you'll find a lot of information...

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¹ - Some use so-called "off-road" X and H-pipes that do not have catalytic converters, however as compared to a "catted" aftermarket head pipe they add much more noise than power.