SO one of O2's on my scanner (autoxray says right side, whichever that is) is cycling slowly (half as fast as my "left" o2) and sometimes just stays at 4mv for 2 or 3 seconds.

They both will stay under 100 mv for 5 seconds max sometimes, i thought it was always suppose to cycle like rich lean fast (ex. 122, 769, 45, 885, etc)?

How should i go about replacing them on a lift? My friend has one i can borrow. Is it neccessary to drop the y pipe?

 

Right is passenger side, left is driver side. For single cat OBD-I cars, RH side generally requires the use of an O2 socket. The LH side is more accessible and can sometimes be gotten off with a wrench. With the right tools you should not have to drop the y-pipe.

 

j/w if youve seen any symptoms like missfires or stumbling b/c of it.