or can I take them off and not use them.

I am replacing my O2 housing and I don't feel like putting them back on

 

sorry about the double post I was typing a little to fast

 

if you dont use the heat shield, the air will be more dense due to heat increase which in turn may cause a drop in boost...but i dont know how much a heat shield does when it comes down to decreasing intake temperatures...but might as well put it back on...wont do any harm

 

the heat shield basically prevents more heat from traveling upwards into the intake area

 

in a car that mitsu was trying to shed every lb they could i'm guessing the heat shield was important enought to put on there i would keep it

 

i agree 100%

 

i think the heat shield also stop the water going down to the mani from the vent. since the mani is made from iron, it get rust easily.

 

+1

 

the heat shields also help hold the heat in the exhuast system. I would definately leave them on/put them back on.

 

Ok I will definitly put them back on Thanks for all the info,

I have just one more question, do I have to use the sensor in the old 02 housing on the new one.
Im just woundering because the one I bought has a bolt where the sensor would go

 

I believe so......you would most likely get a CEL if no 02 sensor.

Someone with more knowledge care to elaborate/correct me?

 

yes you have to use the o2 sensor, the bolt is in the new one to protect the threads while welding the o2 bung on

 

well the guy who had my evo before me decided to take the manifold heat shield off and now my headers are all rusted up and looks like **** from all the rain comming threw the hood. and when i am washing my car i can hear the water hitting the manifold. that "could" mess it up. my recomendation is keep it on

 

alot of rally cars with bung on the manifold will cut the heat shield so it can retain both the shield AND the sensor

 

well I couldn't get the 02 housing on.

The bolts were on so friging tight I Couldn't get them off with the small 14mm wrench I was using.

but I did manage to get the down pipe and test pipe on, which made the car much louder.
I also noticed a better throtle responce.

I guess I will just have to have someone put it on for me. I just don't have the right tools
and I don't want to take my entire car apart just to replace the 02 housing.