^^^X2 - I can get better results with EGR delete and adding HLC (Hyway Lean Cruise) which adds more SA and leans out AFR to ~16.7 with no KCs. I also replaced my old 2-way cat with a newer 3-way that does reduce NOx.
You will need to add more timing when you go into "lean cruise" Atleast on a LS you need to for it to make any difference. I use to run 93 octane in a Cam/Turbo LQ4 and ran it in the high 16s/low17 AFR and 43-44* timing for cruising at 2000 rpms. Without adding the timing it didn't help anything.
