I have a smog test due (86 22RE) and looking at the results of my previous smog test plus digging thru the board of past posts and this post today:
http://board.marlincrawler.com/index.php?topic=35317.0makes me believe that 22REs have a problem with NOx.
I have 2 theories (I believe it's a combo of the 2...)
1. Carbon buildup raising compression ratio and combustion temperature
2. Better replacement exhaust system.
I'll explain #2. The stock EGR system's EGR modulator takes into consideration exhaust backpressure for how much exhaust to route back through the system (remember EGR will lower NOx).
With a better more freeflowing exhaust, you'll have less backpressure and then less EGR, then more NOx......
Comments.........