I have a 1992 ford 150 with 82000 actual miles and all of a sudden its getting bad exhaust fumes in the cabin. Its getting so bad that you cant run the air conditioner because you have to have the windows down and ,then when you stop your flooded with the fumes along with cars beside you.I had a new exhaust system installed from the converter back about 6 mths ago. Dont know what to do. Would it be a dealer fix or can I fix it? Would appreciate some feed back.......