Dave is NOT very knowledgeable. He argued with me on the phone. I have been a professional mechanic for 30 years. He tried to tell me my truck had 4 catalytic converters. It only has one. I am not sure if he was trying to rip me off or what the deal is. I would not use a place like this. He went from $225 to $1500 before I even brought it in. You would think before saying things like that he would look at what I have. NOT impressed. I will not be a customer of a shop that does business like that.