Slammed430

So I bought a ls430 looking to do a custom exhaust on it n don't want to throw codes can I tune this ecu or do I have to do a standalone please n all help would be appreciated

05ls430518

iTrader: (1)

motec m800 standalone

Striker223

Nuke it from orbit I see lol!

If you just want no codes All4swap can do that plus slight adjustments for headers and such

WILLYumD

If by custom exhaust you mean anything downstream from the O2 sensors (e.g. after the headers and pre-cats), then there shouldn't be any CEL and you don't need any tuning.
If you're gonna be removing the pre-cats messing with the exhaust before the downstream O2 sensors, the 3UZ-FE ECU remap from ALL4SWAP (or Quantum Auto in the USA) that Striker223 mentioned will prevent O2 and cat codes.