pro-flo problems

[Impala Matt]

I recently installed a 1st gen Edlebrock Pro-flo fuel injection system on my ZZ4. The system only had 3000-4000 miles on it.
I purchased the correct chip from Edlebrock for the cam in the ZZ4
The set up runs and drives ok but iI am having one issue.
When I let of the gas pedal, like to shift, I get popping through the exhaust. It happens almost every time I let the gas pedal up.
Just letting off the gas to reduce speed and the popping and banging is constant until I push the pedal again.
Edlebrock says its too rich at high vac low rpm but leaning it out at these setting does not fix it and makes the car run bad
Any one have any experiance with these systems?
It is not lap-top compatable and can be tuned with the calibration unit that comes with it.
thanks

[gkring]

Stick shift I assume since you state letting off gas to shift. is it popping when you let off the throttle and push in the clutch, when you let off the htrottle but still are in gear, or anytime you let off the throttle no matter if you are in gear or not?

[Impala Matt]

It pops any time I let of the gas
If the car is in gear and the engine is pulling it down
or in between shifts

[rrunner68]

I would clean the O2 sensor and check for ehxaust leaks.