As a sales rep driving all the time I often wondered if I should replace my O2 sensors at some point. However since the car has always run fine and never thrown an 02 code I decided to save my money. So FINALLY at 224,000 miles the old '00 TL started to use more fuel but otherwise ran fine so I pulled 'em. The rear one had burned up but the front one looked OK. Replaced both anyway, car is back to using the normal amount per tank. So I'm saying the factory ones can last a long time. Thanks. I also have an '03 CL-S.

 

I have bad gas milage on my 01 CLS and is O2 sensor a possibility that would cause the mpg to drop?.. bc i tried everything to bring it up but it's avg 10-12 mpg without driving hard.. if u know anythin about it let me know.. thanks..

 

wow that gas mileage is horrible!!! hell you might as well pull them out and check em' it wont take you but 10 mintues. good luck with that man

 

anyone knows the location of the front o2 sensor?.. is it underneath the front header?.. i got the o2 sensors hopefully it with fix my mpg problem or makes it better.. thanks.. reply asap if anyone know.. lata

 

Is there any update on this? I'm having the gas mpg drop in my CL after I seafoamed it so I belive it is the o2 sensor as well. But I need to know which one you guys replaced (front or back). Let me know whats up. Thanks

 

/\ if anything its the front. the rear just checks for how well the cat is performing.

 

I doubt if its really that low, are you measuring it right? 10 to 12 mpg is mega size pick up truck territory.

 

im getting about 180-200 miles per tank using about 13 gals, im guessing my o2 sensors are going bad? when i check them should i check for anything else?

also where is the front o2 sensor located?

 

What's your mileage? If it's anything around 100K change them. Front is on the down pipe coming off the headers, 2nd is in the CAT.

 

im at 134000 miles, and thankyou for the info