Anyone good at tuning for emissions test?

[Terminal_Crazy]

Always interested.
Glad it worked.

[daleulan]

This is a bit late but I always use a post-catalyst heated O2 sensor (Bosch LSF4.2 works well) and look for wiggles there. I try to get the front o2 thresholds set to get the rear O2 (with catalyst) reading as close to 0.55-0.6 volts as possible, and make sure that light transient driving doesn't make it deviate much from that. I'm in a pro tuning environment for up-and-coming engines (2024-2025 release) so I have WBO2 and post-cat O2 sensor into the ECM already, a good 'first pass' is getting as many part-throttle transients to average as close to stoich as possible.