I have an 88 with a 5.0, and I want to replace the oxygen sensor as I'm sure it has never been replaced. Problem is, I can't find it! I looked over the exhaust manifolds, and even tried to figure it out from the pictures in the manual, but I still can't find it. Any help?

HAVE YOU LOOKED NEAR THE CATS? ON MY 99 P71 THERE ARE TWO RIGHT NEXT TO THE CATS.

what year is your probe if it is a 93-95 just take the heat sheild off your header and get a adjustable wrench and work it loose then screw it off and unplug it then repeat the steps opiosite of  putting the new one in, if you have OBD2 then you will have to replace the one at the header plus get a O2 sensor for the under your car near your cat I belive and replace it if you have you OB2 you will have to jack your car up to get to the   2nd O2 sensor so dont waste your money on having a mechanic do it, also make sure your engine and exhaust is cold before doing this and disconnect your battery terminal before doing this work and the car will idel funny for a min or so then just drive it and it will be fine.