Quote Originally Posted by 89Vette View Post
Wow...Are you sure that's "normal" for the fleet of VX units? If so, it shows that the WOT circuit must be set to engage at 25% TPS. That's certainly possible -- as it's a "trick" for tuners to do this to make a performance tune/motor seem snappier. It also shows why the people getting the best MPG drive (and I quote) like a tennis ball is under the gas pedal.

Running in closed loop is normal. That's what all motors (should) do after open-loop warm-up. Closed loop means the O2 sensor is providing feedback to the ECM for correction of the fuel trim data.

14.2 is the correct stoic ratio for ethanol (E10). So, that part would be correct -- unless you were running 100% gasoline.
Not a VX - hence 'our' ECU - Jackaroos. Four 3.5 manuals behave the same way.
Well aware of it as a tuner trick - have done it - but not usually seen on OEM setups. Pretty much ditches everything from 25% TPS upwards.
With O˛ and knock sensors it could be much leaner & more advanced a lot of the time
The supercharged units are returning much better fuel economy than the stockers despite being driven with somewhat more *cough* enthusiasm