I just installed the Berk 70mm HFC on my '04 to the stock header. I reused the donut gasket that is in the picture below.



I have two issues/questions and I think they are related.

1. The springs on the bolts are compressed all the way, where on OEM cat they aren't compressed all the way.
2. The cat didn't go all the way into the donut gasket, but I checked and it is evenly seated all around and doesn't have noticeable leaks.

Spring compressed.


Gasket not seated all the way. This is the most it would go in.


Did anyone have similar issue? I think something is not right here.

Should I have bought a new donut gasket? And I'm pretty sure the springs on the bolts should be able move to allow the exhaust to have some freedom.

Thx

 

You need to replace the gasket - it's essentially a limited-time use gasket and will likely leak if not replaced if you are installing a new catalyst. The gasket wears over time because that 'joint' allows for some movement of the exhaust. That gasket has a tendency to leak even when the old catalyst is re-installed. I have the same catalyst and I ran into the same scenario with the springs being almost completely compressed (I used a new gasket).

 

Cool thanks. I thought I should have replaced that gasket. Probably will get one from Rockauto ($11), not OEM ($30).

Does it matter which way you install it? Do you put the gasket on the header first or jam it into the cat?

Thx

 

put it on the header first.

 

OEM is closer to $45 I just had the same issue with my Berk 70mm. The donuts definitely needs to be replaced.

 

I bought a Walker gasket from Rockauto for $12 I believe. Will see how it works.

Also, I have a T1R 70mm single exhaust, so I bought 2.75" (~70mm) ID gasket for the muffler, but it was too small ID. T1R actually needs 3" ID gasket, so it's more like 76mm exhaust...

 

Being that the donut is always shifting, as long as you can get it off clean it can be reused no problem. It's not like you are disturbing a joint and breaking a seal...it's always moving.

HOWEVER...in your case, you have to do something about the spring bolts. You cannot drive with them fully compressed, you are guaranteed to crack the header or test pipe/cat.

Use washers to space the bolts so the springs are not fully compressed.

 

I installed a new donut gasket and the fit didn't change. So, I'm thinking that the shape facing the header of the Berk cat is not exactly the same as OEM.

I'm gonna put spacers so that it doesn't break anything, thx Billman. It's true the exhaust system needs some flexibility, otherwise welds/joints start cracking... So that's why I thought it was strange when I installed the cat.

 

What you need to do is take your old gasket and cut it down to about 1/2" or so ( guesstimate and cut as necessary)
And put it under the new gasket. Should do the trick, looking at the pic you want to tighten up that gap, buying new springs will not help your situation

 

You have to get the BERK closer to the header.

If you do what iaxpL suggested: does it fit better?

Looking at the pictures I say the BERK diameter is wrong for the OEM donut - it simply does not fit.

I bought a new donut once to be safe - to install a new cat.

Looking at the old one (8 years old or more) and comparing it with the new one I thougth... WHY did I buy a new one?