Help... What is this mystery part?

[MR72Chall]

It is mounted on the upper passenger side firewall next to the Electronic Ignition. 1972 Challenger 340
I've tried looking up images but no luck so far.

 

[Xcudame]

It's part of the Smog stuff (NOx system) started in 1971. See diagram form 71 Cuda shop manual. Personally, I would chuck it. Or at least make it for "looks" only.

 

[MR72Chall]

Thank you for looking this up! Been scratching my head for days. I agree. I'll paint it black and put it back to fill the hole in the firewall where that big capacitor sticks through.