73 deville Y-Pipe?

Started by RobW, August 04, 2015, 07:42:48 PM

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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?
Rob Wirsing

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 Myers CLC Member #27431
"The 59' Cadillac says more about America than a whole trunk full of history books, It was the American Dream"

The Tassie Devil(le)

I wonder if it was for fitting an Oxygen Sensor?

Bruce. <:D
'72 Eldorado Convertible (LHD)
'70 Ranchero Squire (RHD)
'74 Chris Craft Gull Wing (SH)
'02 VX Series II Holden Commodore SS Sedan
(Past President Modified Chapter)

Past Cars of significance - to me
1935 Ford 3 Window Coupe
1936 Ford 5 Window Coupe
1937 Chevrolet Sports Coupe
1955 Chevrolet Convertible
1959 Ford Fairlane Ranch Wagon
1960 Cadillac CDV
1972 Cadillac Eldorado Coupe


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.
When a Doctor "saves a Life" it does not necessarily mean that that life will ever be the same as it was, but he still saved it. My 46 may not be as it was but it is still alive.
Sheldon Hay

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?
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason


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. 
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2


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

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. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason