96 850 fuel milage/octane?

guest · Post by **guest** » 10 Nov 2003, 19:28

hello,
I have a 96 850 glt and love it. I've recently been paying more attention to my fuel milage. I've added the "tornado" fuel saver and it did help a bit in the performance (mainly getting on highway and upper rpm situations). I seem to be averaging 15 MPG (about 150 miles to 1/2 tank) I do alot of highway driving that is normally at or above 70mph. My commpute to the highway is about 10 miles (stop and go) and once on the highway about another 15-20 miles. I have been running 91-93 octane (is this too high?) I have changed plugs, air filter, added the tornado fuel saver, checked tire psi. Any idea's?

Post by **matthew1** » 10 Nov 2003, 20:24

Cap and rotor would be a nice addition to your list. Run a fuel treatment... STP or similar every now and again.

Travis · Post by **Travis** » 19 Nov 2003, 08:38

replaced cap and rotor, seemed to help a little but still arround 16 mpg. No engine light is on however when all dummy lights come on in second ignition stage the check engine light does not light up with all the rest, is this normal? A few lights behind the speedo and tach are out, possibly the check engine light is out and is actually on but there is no light to inform me? Autozone suggested o2 sensor but i'm not about to drop $150 for something that isn't wrong

Post by **matthew1** » 19 Nov 2003, 10:53

Dollars to donuts it's your O2 sensor and you don't know it because the check engine light bulb is burned out. Have your codes read. Bet ya got a 2-2-2, front O2 sensor.

digital2 · Post by **digital2** » 20 Nov 2003, 07:46

have somebody rev the engine and u look at the exhaust. Do this when engine is hot with temp gauge at 3 o clock.

If u see black smoke then u

1) need a new O2 sensor

and or

2) have vacuum leak between MAF sensor and intake manifold

Travis · Post by **Travis** » 24 Nov 2003, 07:16

I went and got readings done (Auto Zone, text no codes) and it came up as secondary air injection. I've heard that could be air pump related (i hope not). Any other idea's?