lack of power, rough idle

1997 ford contour 2.5 l v6 120K miles, vehicle idles rough and often stalls at red lights. Lacks power and consumes gas. I have replaced wires, plugs, air filter, fuel filter, MAF and IAC. Also replace intake gaskets, appears to be excessive amount of oil up by the intake gasket after driving it awhile with the new gaskets. Plugs are dark. What do you suggest?


I cannot detect any air leaks. help.

Thanks bob

[email protected]