Question for the tuners: Can you program flat foot shifting without

[UrS4boy]

resulting in flames and backfires?

[my2000apb]

nope

[prj]

Easily. Cut fuel instead of spark, done.

[my2000apb]

any issues from a lean condition?

[prj]

any issues from a lean condition?

There is no lean condition.

You are cutting fuel. There is only oxygen/air, nothing to combust. So it's not "lean".

[UrS4boy]

Easily. Cut fuel instead of spark, done.

Thanks. Any videos of the results of such programming? What about the arguement that leaving the fuel on and cutting spark results in raw fuel exploding in the exhaust manifold - which provides an anti-lag efffect?

[prj]

Because you are not closing the throttle, you don't slow down the turbo nearly as much.
Yea, it's not going to be as good, but manageable enough. What kills the boost is mostly the throttle closing.