Failed emissions, and a few Q's

[Juice]

2005 Grand Marquis, failed for two monitors not run. O2 heater related. Returned to stock, monitors ran and completed in one drive cycle.

Loved the shift firmness, but MPGs did drop 1-2 mpg. Averaged over several tanks of fuel. Tune was in car for several thousand miles.

Is there a way to see the differences between the factor tune and the 87 octane canned tune? I would love to keep the trans mods but get some of the MPG's back.

Second, I have to rebuild the rear diff due to noise and leakage and will be installing gears. So the PCM will need to be programmed for the new ratio. This presents the problem with the emissions test, as I don't want to keep resetting to stock every year.

I may even pay to reset the Intune to use on another car after I made the changes to the GM. So at this point, going to Ford and pay them to set my gear ration seems like the only option without emissions issues. And that costs about the same as paying to reset the Intune.

Please advise,

Thanks

[tuningss]

Juice, a custom tune can handle all of your needs including the gear ratio change. We can help you with that or any of the Diablosport CMR dealers you find on the locator.