My Blazer has a 350 30 over with 262 xe comp cam, flat tops, k&n, helix power tower, chip, And flowmasters. I let it sit for a few months when the tranny was slipping, And ever since it smells like it is running very rich. It is so bad that it burns my eyes, And i can see it fuel smoking. how should i go about fixing this? Can a bad oxygen sensor cause this?