so i was power washing under my truck 95 12V yesterday, trying to find where the oil is leaking from, it's more like wheres it NOT leaking from... wow... it leaks alot,

anyhow. on the exhaust, saw an interesting little something.. can anyone tell me what it was once used for?

Looks like some sort of emission stuff, or someone had their crank case vent plumbed there to draw out pressure from engine. 

1 minute ago, Dieselfuture said:

Looks like some sort of emission stuff, or someone had their crank case vent plumbed there to draw out pressure from engine. 

 

I would guess it was originally attached to the cat. No clue where it goes on the engine side.

4 minutes ago, NIsaacs said:

 

I would guess it was originally attached to the cat. No clue where it goes on the engine side.

Nah it's to inject fuel in exhaust to throw flames out of tail pipe 

Did 12V's have cats on them? 

28 minutes ago, dripley said:

Did 12V's have cats on them? 

My 97 has a catalyst on it. It was purchased and has been in New Mexico it's whole life.

It's a secondary air injection, SMOG, pump check valve.  It's used to keep exhaust gas from flowing back to the air injection pump.  When the valve fails the exhaust gas in an on demand pump will flow back and overtime ruin the pump.  

 

                                                     

That was something I had wanted to do to my IDI.  I wasn't comfortable venting the CDR to atmosphere but didn't really want it going through the intake either.  It smoked far to much, to the point of people telling me the truck was on fire.  Venting through the exhaust was an option I considered but then didn't really want all that oil mist in my pipes either.  I ended up installing a home built catch can and a custom intake that allowed the fumes to go in after the filter so they weren't soaking up all the oil.