Originally Posted by Domvr6
ive noticed that the gaskets are bad. i thought my leak was from the oil filter housing, so i changed it but i think the oil pan and valve cover are leaking.
is there anyway to check if one certain O2 sensor is bad? i bought one then realized there are 2 before the cat and then 2 after. i believe only the ones before the cat are bad.
I personally don't know how to check. Back in January, my shop hooked my 540 up to their diagnostic computer, which indicated that all 4 had to be changed.
DO NOT buy them from the dealer. Dealer sells Bosch sensors which can be picked up for over half the price if you shop around. Here in Toronto, dealer wants $330 each for the back pair. I found a shop that sold them for $90. Fronts are cheap, like $30 or 40 each.