[alfa] Re: 164S Smog Test Failure - Suggestions How To Pass?

[Brad Anesi <brad.anesi@xxxxxxxxx>]

There are several potential contributors, but the basic cause of high NOX
emissions is a combustion temperature that is too high.  This can be caused
by:
1) Too much ignition advance  (Is your Motronic "chipped"?)
2) Compression too high (Could be caused by carbon build-up)
3) EGR not working (not a factor on the 164)
4) Overheating engine
5) Partially clogged catalytic converter
6) Improper fuel octane (Are you running Premium?) 

Of course, high NOX could also be caused by an ineffective catalytic
converter, as that is one of the gases it is designed to "clean up".  

Since you're close to passing, you should be able to get the motor to pass
without too much effort.  On a motor with factory adjustable ignition
timing, I'd have it passing in 10 minutes by retarding the spark a couple
degrees.  You can actually get a couple degrees of adjustment with the 164,
but opening up the mounting holes on the crank pickup, but clearly that's
not a factory-endorsed method.

Brad  
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