Heat riser?

[burgundy83]

Is it really worth trying to re-attach the control thing or buy a new one, or could I go without it? I'm not sure how well these things work.

I was told this thing was my cruise control lol, did some poking around and it's definitely not. Found the broken bracket and everything. I just took it out and plugged the vacuum line from the thermostat housing for now.

 

[jmt455]

The heat riser forces exhaust gas under the cab base to help pre-heat the incoming charge.

Cold weather warm-ups will be slower without a functioning heat riser and your vehicle might not pass a "cold start" emission test, if that's a concern.

You can certainly eliminate the valve. Easiest way is to remove the butterfly plate on the valve or remove the butterfly and shaft completely. If you remove the shaft, you will need to weld or otherwise fill the holes in the valve casting to prevent exhaust gas leakage.

 

[Bonnewagon]

Removing it is not so easy as the manifold is flat at that point to mate to the EFE housing. You need it there to mate to the head pipe. Best to baling-wire it open or just get it fixed, and they are not cheap these days.