[wrogers55]

While you are at it, have a close look at the mass-flow meter on your system. If the manifold is that bad, you have another bigger problem. Three little, really little, wires across the air inlet of your mass flow meter. If they are coated with "anything", the meter will report bad information to the computer. The result is usually very poor fuel milage and poor throttle response, at the least. Clean them without touching them if at all possible and only with something made for the purpose. Brake clean or carb cleaners will likely leave a residue on the wires and cause the same problem. In the worst case use a stream of isopropyl alcohol, better case is a spray can of cleaner made specifically for the purpose from the auto parts store. Don't break the wires cleaning them....$350 or more to replace that little jewel.

I'm not that smart, just lived through total frustration with this exact problem once upon a time........