Re: why the significant gas mileage difference?

Jim Yanik wrote:

> Or maybe you were low on coolant and the sensor was not immersed in it.
> Sorry,but thermistors don't get "tired". Maybe it changed in
value,skewing 
> the ECM map.An ohmmeter would tell.
> 
> but your comment made me think I should be checking my SpecV's CTS and 
> coolant level,as my mileage is a lousy 18MPG.(72K miles)
> That and the primary O2S.

Not in my cars. Whenever I have a problem I always rule out the basics; 
low oil level, coolant low, need of a tuneup, etc.

I always try the least costly solution and move up.

I bet your primary O2 is done. With the CTS, the basic symptom is that 
you should notice that your temp gage sits a little lower than what your 
normally see.

CD