I left my truck at a relative's property sitting outside for about 5 weeks without running it (doesn't fit in garage) and when I went to pick it up I found that rats had built a huge nest in the engine bay. They had piled up leaves and twigs and crapped everywhere, chewed up the insulation and hood liner to create a soft nest, and chewed all the way through what I believe is the EVAP emissions hose (goes from top of intake manifold to a small black box/fuel line on the firewall above brake booster).

a) is it safe to drive without this hose on until I get it replaced in a couple of days? I know it will probably throw codes but thats OK.

b) I cleaned out the engine bay as best as I could, but some of the leaves fell down between the heads, block and intake etc and I can't get them out. Do I need to worry about them catching fire when the engine gets hot?

 

If the line is open to manifold vacuum, plug it.