ive been searching for along time on here about the stupid opti and and seems that ac delco is pretty much the best for a bolt on or mild cam car..well this is my 2 opti that went bad in a year n half and thats only like 5 to 7 thousand miles...im not installing them my mechanic is and he doesnt kno why they are failing either..my computer is set to shift at 6000rpms so i kno im not killing it from revving to high..i rarely drive it in the rain its not my DD so do you guys think hes installing it wrong...what are they main things he needs to do to install it..im going to have him check the opti harness and optical sensor connection for corrosion is there anything else i need to tell him.. thanks guys