jyeung528

Out of curiosity, the 2006+ s2000's no longer have the secondary air injection system.

What do they replace it with?

It doesn't look like it's replaced with anything, so how are they achieving reduced emissions at cold start up? Isn't the secondary air injection required by emissions laws?

stewpitt

IIRC 2002+ ap1's dont have the air pump either? Ive heard the 2000 and 2001 ap1 ecus run rich. Maybe the air pump was there to compensate for early model tunes from the factory?

noodels

dbw TB and ecu modifications to meet requirement standards.

Billman250

Air pump present 00-05.

jyeung528

Based on secondary air injection systems helping to burn excess unburnt fuel at cold start, would you be able to elaborate how dbw or ecu modification would help burn unburnt fuel in cold start situation? Do these modifications relegate secondary air injection as obsolete? My dbw Audi still has secondary air injection, couldn't they also modify the ECU and get rid of secondary air system just like Honda did?

noodels

Have on my 04-05.

noodels

its in the fuel tables from factory ecu,thus built in for regs

noodels

pps its only there to heat up the cat

jyeung528

Right, heat up the cat for a couple of minutes at cold start.

So how is an ecu modification heating up the cat at cold start without the secondary air injection? I'm curious about the actual method that allows them to completely remove secondary air.

noodels

A module or a resisitor in place.