OVERLAP and HYDROCARBONS Question

[Chris Pronios]

Not urgent but would appreciate some input.

Euro-speced SR20DEs (up to 1999 I think) are all high-ports and similar to
JDM engines as far as emmission paraphernalia are conccerned.
Tthat is they have ... NONE.
No EGR, no AIV, nothing but the cat and O2 sensor (if you consider the O2
emmission equipment).

A friend tested a rather new N2K (originally sold in 1997! - now with only
close to 30.000 miles) with S4s and the hydrocarbons were very close to the
limit (actually they were above it but they made do with retarding advance)
during IDLE (900rpm). Now, just below the limit in idle for a 40K miles
engine and catalytic converter probably means decisevly over the limit in
anything else. HC emmission after idle 2500rpm were just fine though).

This would mean that plans for S5s in my 100K and 12 years old engine are
probably scratched!!!
Even S4s will probably put it over the HC emmission limit at idle.

Any ideas on how we can specifically avoid/reduce  the high HC emmissions on
idle?

Cheers,

Chris