Whats wrong with the 00+ Celica GTS?

Hey, im not a BIG Celica GTS person, but if i cant get any other import, its gotta be the Celica. Anyways, i heard the 00-04 Celica GTS is "hard" to modify? i hear something like "it has a ECU in the car so you cant really modify it that well" and other stuff about the ECU and all. Can you guys tell me how to deal with the problem if i get the GTS..? thanks

the 00-01 celica gts runs like 14.4 at a 1/4 mile 02- runs slower because of the revised ecu, there are mods out there but just not big ones, i would supercharge the car, blitz has on supercharger that boost the car to like 240hp and 250lb of torque, im not sure if its available for us here in the US but otherwise its good!

hard to f/i 00 + celicas because of the high c/r

whats the compression ratio on the 00+ Celica GTS? Compared to...an Eclipse GSX, whats the c/r of both?