I mashed my left cat real good. It is flat and hollow now. I don't know a lot about the emissions system, but will this throw codes and mess up my fuel/air? I've been driving like this for a week with no problems, then last night I went for a long drive and got an engine light. I imagine this is the problem, but haven't checked it yet. Do the O2 sensors compare to side to side and well as front to back? I have many things left on my list of cool stuff do buy for the old beast, exhaust was not one of them, I've crushed it several times 4 wheelin and putting new stuff on seems wrong....I just can't stand engine lights.