A 1999 Formula with bolt-on's and cam (no heads) has LS1-Edit done by a well-know shop in June of 2002.

The car was re-dyno'ed because a loss of power, and while on wide-band reveals a 12.1 A/F ratio.

No changes were done to the car.

Is it possible for the PCM to "Unlearn" or overwrite the tune originally done?

If it is possible, how would/could it be prevented?

<small>[ January 31, 2003, 10:39 AM: Message edited by: mrb00formula ]</small>

 

"Is it possible for the PCM to "Unlearn" or overwrite the tune originally done?"

The PCM will not "overwrite" any changes made to the "permanent" registers, nor will loss of power to the PCM. It's possible the STFTs/LTFTs will adjust, as these are operational adjustments that the PCM will make.
When you get/make a custom tune, you are placing values in the computers' memory that stay there until removed by the same methods.
There are still adjustments that the PCM makes
constantly while you are driving,using a different type of memory.
Hope this is clear enough?

 

Is COTs disabled or enabled? Also, did they take the time ensure the LTrims would remain negative?

Tim

 

i had my car dyno tuned and the next day the air fuel was all over the place.. I forgot to uninstall my HPP untill i got there. It had to be re tuned because the car learned over time.. has it done a second time and i was all set.

<small>[ February 04, 2003, 10:52 AM: Message edited by: Dave@Ramchargers ]</small>