I had my OR/H pipe and Flowmasters installed last week. I still have the old sensors in the H pipe but my Check Engine light has not came on yet (I was told it would come on). The car seems to be smoking more under hard throttle and it has a bad exhaust smell. I have turn-downs right behind my mufflers so the smell will be stronger because it's closer. Will it help if I put whatever new sensors that I need to put in the pipes? Do they affect the way the car runs?