State inspection emissions can be a pain to pass with turbo cars! Thank you for those that posted their results in other threads - they were helpful. Here's my results so it can help others too.

This is on a 1.8L 1995 Miata, T25 turbo no EGR, MSPNP with high res 10g code, and closed loop turned on (wideband corrected, AFR table targeted).

 

Damn, 87 octane FTW
What does the alcohol do?

 

It burns cleaner than gasoline (lower HC), leans out fuel, and also has a cooling effect (lower NOx). My thought process is to target fuel a little richer than it should be then dump about a quart of alcohol to lean it out and reap the benefits. It may be overkill/unneccessary in some cases but I've had good results doing this method so far. If you do not add alcohol, I would probably target 14.7AFR @ 25MPH and 15.0 @ 15MPH.

 

Interesting. I targeted 14.7:1 and left timing alone. Passed fine with a new cat.

Most people fail because of High NOx due to aging cat. Which can sometimes be remedied by going a little rich and a little hotter exhaust (retard timing).