I've a 1999 Olds intrigue (3.5l/94K) that's been getting awful fuel
economy for some time now and nothing seems to help. For the first year
or so I owned it, it consistantly got 19-20mpg in all city driving. For
the last 1.5 or so years it has dropped to 14-16mpg, usually closer to
As soon as I noticed the huge difference at the pump, I started having
work done but nothing's changed. Thus far I've had new platinum plugs
put in, a $180 fuel system cleaning, tires rotated and balanced and
I've run some chevron techron thru it. I also get regular oil changes
w/mobil1 and just had the tranny fluid changed. I check tire pressure
often and drive pretty conservatively.
People have suggested the next thing I should try is replacing the
oxygen sensor, but both mechanics I've asked about it seem to think it
would be a waste, and that without a check engine light it's probably
So really I don't know what to do, but this problem is driving me nuts!
I gotta think that something is going very wrong, but not knowing autos
very well, or being a DIYer I have to rely on the mechanics. Is there
some kind of diagnostic machine that can find the problem?
Aside from the awful mileage problem, it's been a pretty good car. I'm
just getting so frustrated with this that I'm thinking of trading it
in. Thanks in advance for any suggestions!