5.0 backfires - problem solved!

[SC74]

Just on what I have read I would be looking for a ground or power problem. All of those codes are realted to low or incorrect voltage.
I have a bunch of wiring diagrams if you need any, what year is the 5.o from?

Thanks Matt... I am so lost on this efi stuff and don't even know what / where to look. There's only one way to learn though and I'm learning fast.

From reading on classic, the 81, 82, 85, and 84 are all codes that are expected to be thrown during this conversion and nothing to worry about.

The one that does require concern is 22 - BP Sensor. I bought this sensor new, so wouldn't suspect it being bad but it wouldn't be the first part I bought new that was bad either. If the BP casing grounded itself I would run a dedicated ground to it but it's just a plastic housing.