2006+ no secondary air injection system
 

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?

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?

dbw TB and ecu modifications to meet requirement standards.

Air pump present 00-05.

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?

Have on my 04-05.

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

pps its only there to heat up the cat

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.

A module or a resisitor in place.

just like a decat sensor..

I think I found the answer, quoting someone on another forum:

Bosch claims that its fuel injection systems do not require secondary air injection for closed-loop operation unless engine displacement is relatively large¹. This is because the air-fuel ratio metering is fine enough for excess, unburnt hydrocarbons to not be an issue.

The 2006+ do use a newer different fuel injection system, so maybe it's this Bosch system.

obd systems have been in place for a while.<on board diagnostics>
the system is common place.
what ever the system, just depends on the program of the ecu

delete

delete

delete

PGMFI

To make things more complicated, euro spec 06+ vsa models, still have secondary air injection. Based on other Honda’s I ‘ve seen, I guess honda retards timing on cold start to heat the cat fast and dbw compensates for the loss of power due to timing retard. This is probably how the cat is heated in USDM 06+

it's either this, or the new Bosch injectors they use in 06' that can meter the fuel better.

EUDM 06+ has the new injectors and still use the secondary air injection. Who knows

maybe EU implemented had different emissions requirements. who knows

True