Well i have read a ton of threads about valve stem seals and piston rings, but alot of mixed answers and opinions come up. I just want to know FOR SURE whats making my car smoke before i work on it. Im pretty sure its valve stem seals since it puffs on startup and puffs from stoplights on occasion but there are other symptoms that are making me weary. Whenever i floor it through a gear then shift and cruise a puff comes out. I opened the oil fill cap and no oil or smoke comes out and there is no oil on the tip of the spark plugs so thats good. I need to compression test it but do the autozone read accurate or should i go to sears?