Hi all,

Just got my van inspected and it failed the emission portion of the test
and the gas cap test. The only portion of the emission test it failed
was the high speed CO portion. The state standard is 1.20% my van tested
at 3.31%

The van has a new cat, muffler, new plugs and wires, new rotor, air
filter, fuel filter. The van is in good tune.  The van is an '85 with a
newly rebuilt 2.1 wbx (with < 10000 miles on it) and Digijet FI (with a
Vanagain high performance ECU). Since I installed the new exhaust, the
van backfires when I come off the gas and the engine has no load. If I
give it any gas at all, whether it is in gear or not, the gackfiring
goes away. The backfiring is not loud. It is more like a string of
softer crackling backfires, it sounds like the way green wood crackles
when it burns or a small string of muted firecrackers. I don't know if
the backfiring is related to the failed emission test or not.

Any ideas for what to check would be appreciated.

Thanks.
Sam