Catalytic converter cover

[CtrMint]

Hey all,

I’ve started to remove some of the IVA trim bits typically added for the test and was wondering whether owners typically remove the cat heat shield?  It’s not the most attractive thing, but I appreciate the purpose it plays.

cheers

 

[Manstein]

Mine departed with the cat.

[Jonathan Kay]

There's some recent discussion in the archives. IIRC most people thought that not burning oneself and other people was the most important factor!

Jonathan

[CtrMint]

Appreciated, although having properly burnt myself on a 7 exhaust back in 2014, I’d say there is sufficient heat to do damage in the silencer.  Though I do appreciate the cat is much hotter.

[John Vine]

Personally, I would advise strongly against removing the cover, as the cat gets extremely hot (much hotter than the silencer).

To improve aesthetics, a cat bypass pipe would be a better idea (if you can find one).     It also has the benefit of extending the life of the cat (assuming you need to refit it periodically for whatever roadworthiness test the IOM operates), especially if you happen to suffer from the odd bout of misfiring (should a coil start to fail, for example).

The link above shows P/N CSP899LC, which is what I have on my 2008 R400D -- I'm assuming your 420R would use the same.

JV

[rj]

Keep it and keep the cat unles you have very good reasons not to. This will save you the hassle to refit it at MOT time.

[John Vine]

...I’d say there is sufficient heat to do damage in the silencer.

Oh yes, and that's the reason I retained the original guard with the latest non-guard silencer:

JV

[CtrMint]

There isn't any emission testing here, so cat deletes wouldn't cause any issues with MOT or other types of testing.  The car didn't even get a noise or emissions test during the recent SVA inspection.

However, doesn't the cat bypass/delete require a remap as it will change how the car breathes plus cause issues with the lambda sensor measurement?  Or is the 420 ECU with a simple removal?

Btw, I don't have a shield around the silencer, it's just a small shield over the cat which is forward of the silencer.

[John Vine]

I don't think remapping will be necessary.  Certainly I've never bothered and the car runs just the same with or without the cat.  And the lambda sensor operates just the same too.

...I don't have a shield around the silencer...

That's the current standard.  My original silencer came with the full guard, but when I bought an almost unused new-style silencer from a 620 owner, I decided to retain the guard.

JV

[CtrMint]

Just had a look at the bypass pipe, yeah bit pricey to just remove the shield, don't think the wife would approve of that one.

[John Vine]

Perhaps you could persuade her on the basis that it would be an excellent investment to "protect" the much more expensive cat? 

JV

[CtrMint]

I’ll try, and post back later, let’s how I get on!