Okay so I went to another mechanic for a second opinion. First one told me I needed to replace the whole engine. The other tells me I need to replace four coils. I asked if he was sure that was the problem. My 00' LS was running rough and had a slight knock. I opted to get the coils replaced, received the call and was told the computer is fried because the coils are not responding. This sounds like horse crap to me but I want to know if this is actually possible? Also this mechanic told me I had to take the car to the dealer to purchase and install because it needed to be flashed. Anyone know why? and is it possible to get away with not going to the stealership?