School me on SC exhaust systems!

[BKC]

Hello all! I was hoping that someone could explain to me how the 911 sc exhaust systems worked as well as what exactly back-dating is. I see (read) about smog pumps and EGRs and thermo reactors but can't find a place where all that stuff is explained!

What was the intent of the smog pump? I see some cars for sale with the belt disconnected.

What are thermo reactors?

Did they have catalytic converters? (air sensors were for 3.2s, right?)

If you didn't live in a smog test area and you were going to disconnect the smog pump, what else would/could/should be done? Is that where SSIs come into play?

So confusing!

[schumicat]

the sc didn't have thermo reactors, thank God. that was the mid 70s cars. only the 78-79 (80?) SC had smog pump. it reduces emissions by adding air to exhaust. yes they had cats in the US version.

[tcar]

As s-cat said, the T-Reactors ended with the '77 2.7.

SC's:
In the US, 78-79 only had air injection pumps and a cat, but no O2 lambda sensor. The pump injects air into the exhaust ports to help burn emissions.

Euro SC's still had smog pumps also a couple years after that as well.

In '80, the US cars got rid of the pump and went to an O2 Lambda sensor with the cat. So Lambda sensors started with the 80 SC, not the Carrera.


Some states/counties/cities require the smog pump to be intact and operational to pass emissions, some don't at all.

Some states will test a car that old once and not require more tests, so once they pass, people remove the pump belt or take them off entirely.

They are ugly and clutter the compartment, but don't really take any power to run... way less than A/C.

That help?