This has done my head in if anyone can solve my problem id de very happy,my car is a 2001 1.8 zetec petrol the problem is when the wheather is hot and i put the car underd load ie drive up hill it pinks its head off and reduced power ,only happens when hot wheather ,this is what has been done so far ,haed off and checked new gasket etc ,mew maf ,crank sensor ,cam sensor, timing belt and pulleys ,oxy censor ,cht censor is woking fine ,cooling system is ok all been checked ,and the correct oil 5w30 and finally new plugs and leads ,oh forgot one more thing a new tps fitted as well ,