im wondering

I see all these post about people needing MIL eliminator or get their chip programmed to get the computer not to read the signal coming from the rear o2 sensor... but here's whats funny on my car the cat where so badly blocked and i had no money to buy an x pipe with car, so i emptied them and that was in november... so all 6 of them now are still emptied and the check engine light never came on is it normal or do you think that the guy before me might have chipped the car? I just got it in august and its a 98gt

it's not burn because when you start the car the light comes on with all the others, the only thing that annoys me in once per month or so the air bag light will flash a few min then stay on, and when i start the car next time it's gone for a month or so