where is the oxygen sensor located
check engine light stays on on 1990 Chevrolet 1500 Pickup
Under hood, driver side, lower engine area, above exhaust pipe flange, mounted in exhaust manifold.
go to the auto parts and get them to put it on the compu. and as long as your check engin light is on they can tell u what is wrong with it and show u where and which one it is. they can even print it out to where it is on your car or truck. and best of all it is free for them to do that.