73 deville Y-Pipe?

[RobW]

Anyone know what the reason for this protruding piece of pipe? There's one on each leg of the y-pipe just below the flanges that attach to the exhaust manifold. I'm assuming this is an original part. The reproduction pipe I bought doesn't have them. So they must be there for a reason? Are they necessary?

[Coupe Deville]

wow.... I have no idea what those are. I know the 73' engine had an EGR valve and some other new things but I do not know what that is. At least my 72' CDV doesn't have those and my exhaust system is all original. As long as there's not anything connected or attached to them, I don't think you should have to worry about putting the new ones on. 

-Gavin

[The Tassie Devil(le)]

I wonder if it was for fitting an Oxygen Sensor?

Bruce. <

[Smedly]

I don't recall those on the 73 deville I had, but I cant be sure that mine was original, although the car was parked in storage in 1980.

[TJ Hopland]

The EFI option was not till 75 and I don't think an o2 sensor was a optional part of the system till fairly late like 78?

I have never seen anything like that before.   I almost wonder if it is some sort of an aftermarket pipe or add on to add side pipes or something like that?

[35-709]

When I got my '73 Caribou it had a '76 500 engine in it, the exhaust pipe on one side had that protrusion.  The other side had been replaced because the car had dual exhaust added.  No idea what function that protrusion serves, but would like to know. 

[RobW]

I'm pretty sure it's the original pipe. Here's a better look

[TJ Hopland]

I will be curious to see if anyone actually knows the answer.  They seem to small and close to do any good for sound or tuning.   Seeing the whole assembly I don't think my theory of an optional side pipe makes much sense either unless you were going straight out the side which would seem like a very limited appeal option on a Caddy unless it was a superfly sort of thing.