he seemed like a nice guy but it didn't seem like it worked and those ball compasses are terrible, those things never work right. It was basically a remote gas tank, he proved an engine will run for a bit and then die when you turn the microwave on with a shitty fuel mix, then he poured more gas in. If there was plasma being formed in that plumbing it would burn any fuel that it hit it well before that fuel could get to the engine to combust and of course it would melt rolled steel.
Unlike the other three states, solid, liquid, and gas, plasma does not exist freely on the Earth's surface under normal conditions, and can only be artificially generated by heating or subjecting a neutral gas to a strong electromagnetic field to the point an ionised gaseous substance becomes increasingly electrically conductive, and long-range electromagnetic fields dominate the behavior of the matter.
https://en.wikipedia.org/wiki/Plasma_(physics)
if exhaust gases where hot enough to generate plasma we would all have plasma shooting out the tailpipe.