i recently changed my air filter and my mpg went up pretty good---but now it has slowly dropped to 17.5 mpg avg.--my guess is to replace the oxygen sensors---where are they located and how many of them are there???---i replaced the plugs and wires last year--so i don,t think it will hurt to replace the 02 sensors---is there a web site i could go to that would have this info??----thanks
99 deville---any ideas on how many oxygen sensors are in my car??
As I recall, your DeVille has a slightly unusual set-up on the O2 sensors. You have three upstream sensors, one in each exhaust manifold and one in the Y-pipe before the cat and one downstream sensor. However, when you purchase them, them have to request two upstreams and two downstreams, the difference being harness length and maybe a different connector. I'm not 100% on the connector.
All you have to do to replace them is disconnect to electrical connector and loosen the sensor using either the appropriate O2 sensor socket or where you have the space a 7/8%26quot; wrench. Your car is pretty tight on space.
99 deville---any ideas on how many oxygen sensors are in my car??
YOUR CAR HAS FOUR O2 SENSORS
THEY RUN ABOUT $60.00 EACH
NOT REALLY SOMETHING I WOULD CHANGE UNLESS IT WAS NEEDED
2 OF THEM ARE UP BY THE EXHAUST MANIFOLDS, TWO ARE AFTER THE CATALYTIC CONVERTORS
