I have a 1998 audi a4 quattro 1.8t and i have problems i hope someone can shed some light on. car is extremely slow has had no power at all since i bought it(figured hey im sure whatever is wrong with it i can figure it out and get it fixed right?). showing codes for random/intermitten missfires on all cylinders,temp sensor and brakelight switch. i also have bad abs module. car is not throwing a cel and is not running terrible other than it can lose a race to a bicycle. so here is what i have tried.... replaced ignition coils,temp sensor,brakelight switch,sparkplugs,installed new valvecover gasket,diverter valve,checked for vaccum leaks and still all same codes appear. and the weird thing is when i install a new temp sensor it works for about an hour showing the temp in the middle and not being all over the place and then stops working again??? its driving me nuts any helpfull advice or things to look for would be much appreciated!