Holley Sniper EFI-Complete system-$600 OBO

Sounds like some of the issues I had with my Sniper system, mine would backfire under load, tried everything to eliminate it but, I ended up ditching the the hyperspark distributor and coil and stuck the stock ignition back in and the sniper worked great then. Those components are really sensitive and require perfect voltage and grounds and I like you got frustrated, now those parts are back in the box in my garage cabinet.