1996 Chevy Corvette with 70k miles and Auto trans. LT1 motor. The check engine light came on and posted P0401 code. Heres whats been do so far: New EGR, New MAP, all the vac lines are clear, removed the intake, heads and all have been tank washed, cleaned, valves redone, oil pan dropped cleaned all new gaskets on top end, exhaust and oil pan. Also replaed the return tubes from exhaust manifold to intake. Cats are fine and back pressure tested fine. I have done everything I can think of that would clear this code. The motor was tank washed because there was some sludge in the top end which I thought was contributing to the problem also it need to be cleaned. I had pass emmissions via the computer 3 or 4 times, went to get the car tested and passed at the emmissions center....on the way home the light came back on pointing to P0401. Could it be the computer (ECM), MAF, another sensor although nothing else comes up on the diagnostics other than P0401. I'm lost. Not a leak and runs very strong. No noise or anything. Why am I still getting insufficent flow?
Nov 14, 2007 at 9:48 AM