Emissions Test / Drive Clean & Methyl Hydrate

[John Chia]

Help!

I'm having trouble passing emissions up here in Canada with a 95 200SX
SE-R.  HC is approximately twice the limit (79/150) and NOx is at 800
where the limit is 600.  CO is passing & idle is clean.

I've replaced so far:
 - front o2
 - cat
 - rotor/cap/plugs (wires are like 1 year old)
 - air filter
 - timing to 13 degrees.

The new plugs haven't been tested but I doubt it'll make that big a
diff.  They're NGKs while what was in there were Bosch plats.  According
to the Unplug-O2-Sensor-and-run-at-2000-rpm-for-30-seconds test I have
an intake leak but all 3 vacuum lines are tight and the rubber isn't
cracking.  Could this be specific to older se-rs?  It also gave me a
MIL. I'm pretty sure EGR is fine but I haven't taken a look as it's a
PITA to get into that spot.

The car was doing really light duty (grocery runs -- i know, I'm going
to hell) for a month or two before the test and hasn't been on the
highway for a decent run in awhile.  Would giving it a 2 hour freeway
jog or so help it?  Even more, like 4 hours?

An ex-mechanic friend of mine suggested I dump some methyl hydrate in
with gas which he says will burn the fuel more completely.  One page
mentions on the net that it's not good to use with fuel injection.  He
usually works on beaters, so i don't know if I should trust him this
time...

Sorry for being so long.  Any help is appreciated.  If there's doubt a
long drive will help clean it all up, and if there's even a little bit
doubt if methyl hydrate will be safe, I guess I'm digging into EGR.

Thanks in advance.

John.