I've been always taught that heat is the enemy of an engine. Especially when it comes to making power.

Looking under my hood today, I decided that I was going to disconnect the tube because heat trying to mix in with cool air seemed really pointless. So I disconnected the tube and removed the shield that went over the ehxaust manifolds.

My question is why?Is it just a smog requirement?Does the intake need to run off of heat from the manifolds? I ask this because I disconnected the vacuum lines from the airbox and next thing I know my engine is misfiring. Because if it's something the engine needs to run properly, I'll put it back on in a heartbeat.

The only other question is taking off the shield I finally got to see the manifolds. They sorta look like headers. Do they have any performance benefit on the engine at all? Because I'm thinking if not, I might have a custom header with room for cats made up eventually.

 

Dude put everything back where it was. Your messing up your engine and eventually you will screw your car up.

Just let everything alone till you get turbo your car. And when that times comes around have a professional do it.

 

That heat is part of your air-fuel ratio balance. It is "controlled" when engine hot or cold. It is there to create a "desired" air-fuel mixture for ideal combustion. That's why you get the missing firing. Remember, engine combustion has 3 main ingredience, air, fuel, and spark.

 

The preheater hose is for your car to start up easier in colder weather.

The heatshield is there for an obvious reason. What does a heatshield do? I think you know.