ok so here is my problem ,check engine light was on for o2 sensor went got them fixed new in the box both of them also the car has an aftermarket exhaust iam not sure of the name but i have a headmen header that came on the car ,and also it looks like a high flow cat on there...my issue is that the check engine light is still on for the o2 sensor code,yes i had it turned off at the shop also the car sometimes boggs in low rpms and help would be great thanks alot guys and girls