Not much out there! I search daily to find stuff for the TrailBlazer with no luck.
Borla makes a cat-back exhaust (not sure if it will fit the EXT). The cheapest i found is $904.80. Stainless dual out the rear. They are the only ones I have found.
http://www.borla.com/automotive/?mak...R&year=2002-03
There are a few exhaust tips out there as well. I know K&N is working to get a 77-Series CAI out.
Volant has a CAI out (never seen it or heard anything on it)
http://www.volantperformance.com/Products/vtchlist.htm
not really much in the way of performance out for it.
you can check this out for some ideas:
http://truckperformance.com/vehicle....f3=Trailblazer
chris