My dad owns a 1995 Bonneville SSE and he has been complaining about very poor fuel economy. The car does not have a CEL or any obvious signs that something is wrong.
My little brother that also drives the car says there is a strong gas smell when you drive the car...kind of fills the cabin...but there is no physical leak...

I thought maybe the cats might be clogged, but the car accelerates fine...not as if the exhaust was blocked.

I have no clue whats wrong with it. I thought maybe O2 sensors, MAF/MAP sensor, or fuel pressure regulator...any other suggestions?

I'd like to figure this out for my dad; thanks for the help.

have the same problem, changed the MAF,changed the fuel pressure regulator. Im thinking either the crank sensor or most likely the O2 sensor.

I would start with changing the O2 sensor. Clean the MAF and change the plugs and air filter. It sounds like your running rich and over loading the cat.

Thanks for the suggestions guys... I will sure try those and report back.

In the meantime, keep the suggestions coming!!

Dan, I haven't looked under the hood in detail yet. But how many primary O2 sensors do these cars have? I figure since its a V-6 it would have 2... Should I stick to GM parts or would generic autoparts do (wagner, bosch, etc)?

Also, for cleaning the MAF, just use a generic autoparts MAF spray cleaner?
Any recommended plugs or do Bosch platinums work fine?

Thanks for the help!!

There'* only one O2 to be concerned with. It'* the one in the rear exhaust manifold.

Wow, thats strange, I wonder why didn't they use two...one on each bank?

Thanks a lot, I can let my dad what to buy... Any preferences on brand?

I forgot to add that the car only has like 70K miles...it barely gets driven.

...bump...

Any O2 sensor should be fine. Just not a Bosh, those seem to not work well in these cars.

Not Bosch... Thanks!!