A couple of weeks ago I reported that a (new to me) 91 Syncro Vanagon
with original WBX engine had failed emissions. Well, after getting
the collective wisdom (most especially from Dennis Haynes) I replaced
the catalytic convertor and installed a new O2 sensor. Topped the gas
tank with gas (from a 10% ethanol fuel source) and got it resmogged.

Passed with flying colors.

Old Emissions
       Limit         Idle               2500 RPM
HC     125           53                 241
CO%   1.00         0.18                0.53

New Emissions

HC     125           14                  44
CO%   1.00         0.00                0.02