Only answer if you know!

Do the 2002 Eclipse GT have oxygens sensors on the exhaust? For example, if I remove the catalytic convertors and resonators will it set off the Service Engine Soon Light? I know it did on My 1998 Z28 Camaro.

Yes it does. If the one in your exhaust manifold is broken, your car will be running beyond rich. If the one after is broken, you car will be fine.

You have a total of 4 O2 sensors in your exhaust if your car is a cali spec. One in each bank of your exhaust manifold and two after your cat. Two if it is fed spec. One in the exhaust manifolds and one after cat.

mine isn't a cali car, but you're saying that i could remove the resonators and cats and the SES light wouldn't come up and it would have no problems or after effects, besides the extra hp??

Resonators make no difference in the overall aspect of the exhaust except for sound. the cat.

I am not sure if removing the after-cat O2 sensor will trip your SES light or not, but it will not hurt the performance of the car. I do not think it will help it either. Why not just get the high-flow cat and cat back exhaust?

lol, cuz i'm short on money. I'll probably just leave the cat alone and get the catback, high flow cat probably wouldn't make any more than 3 extra horsepower. Not worth the price