I actually had it stock for the first test, 5 degrees BTDC with the test connector in. For this one I put it to zero, so less advance compared to stock. Should help lower NOx.
After this test I got a little more HC, but it is still really low. I might go another click rich in the afm. Actually these emissions test are kinda like a cheap dyno pull. Sorta helping me tune the thing. Or that's what I am telling myself so I don't get raging pissed off.
I don't believe that messing with the mixture or ignition timing to trick the ECU to reduce NOx is a good idea just to pass emissions testing. How much time does the emissions testers give you to correct the out of spec test? Are there any penalties?
The 1985/86 22RE is designed to meet Federal EPA standards and certifications, and other emissions requirements. Lean mixture AFR issues and high NOx are not uncommon for these engines, and other engines as well.
The challenge is to diagnose and then fix WHAT is causing the high NOx reading.
Gnarls.