Here's the Setup: long-tube headers with cat deletes, a Cold Air Intake and a pair of 1 chamber mufflers. This is a two part Question:

Part I
If the cats are removing and I do not supercharge or installing a turbo I've removed a significant amount back pressure. I know there's a ratio between back pressure and torque. Additionally, the exhaust valve springs are set with a specific amount of anticipated back pressure by GM. Thus removing back pressure sets me up to slap the $hit out of my exhaust valves or possibly both sets of valves?

True or False

So I'm thinking do not remove my cats unless I mechanically inject air to create back pressure.

Part II
Trying to tune it with a Diablo with the set up listed above will not work.
I should take it to a tuner or put the cats back on with sensors to use a hand held?

I know the PCM is looking for that mvh reading and if it can't find it it appears to default to throwing a ton a gas to avoid a lean condition.

Sarge - what are your thoughts?

Mind you this is not my set up. Another individual on this board is struggling to tune his goat and I think what I've laid out above is why...