Reversing a bad (non cummins) tune

[Rawze]

(10-30-2026 )DVT873 Wrote:  ...
My question is: when somebody "tunes" an engine, does just reflashing it return it to stock?
...

(for red engine ecu's) ...

Putting the factory software (an incal file) back in it will completely wipe it and make it start over with fresh programming. No remnants 0of the old programming will remain.

However: If the work-order/vehicle specific template is backed up while the bad delete program is still in the ecm, then once ecu is factory-restored, if there is any bad data caught up in that template itself, it will sometimes can get transferred into the new program. - The only way to avoid this is to have a work order from BEFORE it was deleted, etc... and restore that.. or take the ecu to the stealers$it to have it done that way.