Hi All,

Yup, my new (to me) 87 Syncro 2.1 Failed Emissions ( for the 3rd time) !!!

Readings: ( and the third test was Way worse than the first two ) !!!

What I did between the 2nd test & the 3rd test
was to get the bus out on the freeway
& hit it hard for about 50 miles.
Kicked the cat many times
ran out the gas & put premium in it.
but readings got worse ???

RPM: 991     %CO2: 11.8      %O2: 3.3    HC: 788   CO(%): 1.53     FAIL

RPM: 2511   %CO2: 13.5      %O2: 1.6    HC: 203    CO(%): .88      PASS

I've changed oil (with 1qt Marvel), filter, air filter.
Plugs, plug wires, rotor, cap

I now have an O2 sensor, & Cat on the way.

My question is;
Will the old muffler affect Emissions?
Should it be replaced as well?

Bus runs quiet enough & I'm going to put a subbie in soon.

What can I do to the MAFM? (clean? adjust somehow?)
Timing? (retard)?

Any & all help much appreciated !!!

thanks,
John C...