I have been considering the same thing but was going to buy cheap summit cats, beat them out for visual purposes and have it flanged so every 2 years i can put the stock cats back in, with stock tune, and get it smoged. Then change it all back for another two years.

any thing to worry about? with that spread?

No one has any ideas? i tried re installing with a different tire size and triple checked the correct fuses and my 04 silverado has the service brakes and ABS lights on. Odd thing is my 04 GMC with another predator programmer dosent have any lights on.

I did not know about the increments of .78. My 04 seems to be always with in one or two but my 2000 will sometimes be as much as 4 increments apart and always the same bank. most of the time just 1 or 2. the 2000 also has 200k on it.
Which bank is which?

After all the good words im interested. What do i need to do, and what does it cost for lew to do a tune?

What if you have a sometimes large spread between bank 1 and bank 2?

i have the same problem with mine and so does my friend