Hi guys been looking around on the O2 threads but could not find any thing really similar to my case. So lets start I have a 99 GP GT and my dumb bro decided to sell the CAT off my GP ,while I was working out of state, since he head you get more hp and CAT's are not demanded to be on a car he in Mexico but after that I noticed car was drinking gas like crazy and the SES light comes on every now and then, some times it comes on right after I start the engine some times it doesn't come on at all, and on other occasions it starts off and then 15 to 20 min later it comes on. had it checked the other day at AutoZone gave some codes don't remember then but guy told me something about faulty inyector, bad O2 sensor and don't remember last one. Any Ideas could this all be caused due to removing the CAT?