So, my car has hit over 50k and the MPG is starting to go down....used to get about 450 miles out of a tank before i got the gas light....now....its gradually getting less and less and since its nice and cool outside i don't see why except that maybe these are going bad. I've read that they start to go out around 50k. So i need 2 of these, and are they easy to change. And i don't suppose someone would have a parts # on hand that i could just type in to order off gm parts direct?

Thanks!

Darby

Yo're doing a hell of a lot better than most of us if you're getting 450 miles to a tank.
I'm getting about 380 miles with only 35k on it ('00 SSEI). I asked several deales about the O2 sensor and they ALL are swearing up 'n down that the 02 sesor is NOT a service item. When or IF it goes bad you WILL see a check engine light. I know there'* quite some conteversy out there on this statement but I have heard this over and over by factory trained mechanics. I'm planing on doing my fuel filter and injector cleaning - see if that helps. There are 2 02 sensors on the SSE'* (1 on the intake and 1 by the cat).and they are approx. $250 for both!!

O2'* are alot cheaper than that. Buy AC Delco sensors at www.gmpartsdirect.com

Part numbers are in Techinfo. Purchase ONLY position #1. #2 is strictly for emissions, not effieciency or performance.

Willwren are you saying i only need to get the 1? Or i need to get 2 #1'*?

thanks much. On order from gmpartsdirect. Hopefully have it in a few days and get my mpg up to some of those higher 20'* that I hear ;P

Man your getting way higher mileage than my 01 ssei. Wonder if it'* because of my lead foot? Today dic read 17.4mpg.