RPM drop

[SIXBANGR]

Not alway's but alot of the time when letting off the gas. The RPM will drop to 200 0r so,. Car stay's running and they come back. Just wondering why. Car has a FAST. Maybe I have something I can change on it?

 

[Lee Thompson]

???

Assuming you have a 2004r trans, it could be that your overrun clutches are not coming on.

 

[TurboDave]

Not alway's but alot of the time when letting off the gas. The RPM will drop to 200 0r so,. Car stay's running and they come back. Just wondering why. Car has a FAST. Maybe I have something I can change on it?

Since you have a FAST, you'll want to address this question in the Performance ECM forum.
They should be able to help you out because there are adjustments in the FAST for just such a problem, just like there are in the stock ECM. I don't know what they're called in the FAST though.