Cat Codes On my GMC 1500 09

[Gunmetal1500]

I am getting CAT codes P0420, P0430, after removal of cats, does this require a custom tune?
1) 288194
2) U7194
3) 09 GMC Sierra 5.3

[Ill_Born_SS]

Yes to disable the codes, but you still require the sensors to be installed and tied up safely. You would have to post a copy of orginal backup and last tune written for the Diablo crew or Lew (06montess). I think its a holiday down south today though!

[06MonteSS]

yep, what Ill_Born said ^ ^ ^ ^