What is this??? Exhaust related.

[Lowe123]

Hello All Im hoping you can help.

short story is...1977 Series 3 88 looking to replace the exhaust pipe as its getting very noisy, with fumes making their way into the cabin, Ive discovered about 5 holes thus far. the question is that there is a strange part hanging off the side of the carb, with a pipe that runs down alongside the exhaust , before connecting into the exhaust below the passengers seat. Having had a look through the manual I cannot find any mention of this part. From some investigating online I think it may have something to do with emissions control.

See pictures of said part:
143031143032

does anyone know what this is, and whether or not it is needed once I replace the exhaust.

Cheers you in advance

[bee utey]

Exhaust air injection valve, a reasonably common ADR27A anti pollution device before catalytic converters became mandatory. It would be a legally required part, but who would know these days. Doesn't look like its been connected for a while.