Did you just notice this happening? You should see if you can hook up a wide band a/f and check that.

 

X2, then you'll just be radiating heat back into the header, which will only make it hotter. An unlit propane torch works well because it's more like a wand, might help you find the exact spot you're sucking air in. I bet your catalytic converter and downpipe are red too. You need to stop running it like that until you get rid of the lean mix.