On my original down pipe from the exhaust manifold is a heat shield enclosing the two pipes. I have to replace this pipe and wonder what the original purpose for the this shield. Is it necessary? Should it be replaced? If so what about header wrap? Even though wrap is detrimental to the life span of the pipe. I've been to two "custom exhaust" shops both of which said we can't fix that. We can't find a replacement listed, anywhere. But if you find one. We will put it in for you". Custom exhaust, I don't think so. A real custom exhaust shop would say sure we can replace that from the cats down, no problem. Sorry for the rant.

 

it’s the heat shield for the cats, helps them warm up. they’re pretty high up and mine’s been off for a long time, just don’t park in really tall grass.

exhaust shop should be able to make a new shield no problem.

 

Header wrap wood be from below cats down. If it's for the cats, why does it go down from the cats to past where the two pipes meet and not just covering the cats?

 

If you are talking about the metal shield that covers the exhaust manifolds, it is there to protect the inside of the engine bay from the exhaust heat.
I have read that if you don't have it you run the risk of melting the nearby plastics.

I have a small crack in mine which hasn't caused a problem, but if there are gaping holes it should probably be replaced.

Can you post a picture of the problem part?

 

 

Sorry no picture. The problem is there is a hole in the down pipe and must be replaced. The replacement does not have a heat shield. The question I needed to ask is do I really need the heat shield? Concenses is I do. So I will see if I can remove it or make a new one. Thank you all.

 

It seems all replacement downpipes with the catalyst don't have the heat shielding that the original part has.
It does seem strange that they wouldn't but I can't find any replacement parts that include them or have them as an additional part if needed.
Could it be that the newer parts don't need that type of shielding?

Sorry this probably doesn't help much. Hopefully someone has more information on these.

 

The Shielding was missing when I bought my XJR ~13 years ago, ~70 K miles later including a few track days and no problems, although I don't need the downpipe catalysts (now removed) for the local emission test, only the underfloor units which are now aftermarket Magnaflow units. I guess you should be ok, maybe avoid long grass as mentioned previously.