Hello everybody, I'm original owner of a 2001 limited 4.7 tundra. I think I have a leaky manifold, tapping sound goes away after the truck engine warms up as it accelerates. I know it isn't the exhaust pipes,, sounds closer to the engine manifold.. I am not sure if it is expensive to replace them at the dealer.. they said two years ago that they replaced a lower manifold gasket but it still sounds the same. I'm afraid they might tell me it is going to cost another 700.00 dollars to fix the same problem. Should I ask them why they didn't fix the tapping sound I thought they had fixed for so much money,or do I take it to another garage to find out if I was ripped off? tia