PRIMARY / SECONDARY CAT REMOVAL need advice who has done it

[JohnRutter]

... This would indicate that said assemblies are indeed genuine but although called "secondary catalysts" their internal construction would indicate they are straight through glass pack silencers designed to reduce back pressure rather than reduce noise.

That's interesting. So surely others that have 'gutted' the 'secondary cats' would have seen that they are indeed just silencers?
And if so, no need to gut them and could remove the silencer box and replace with a straight-through section of pipe, as if they are not cats then not something a tester could complain about having been removed?

 

[R1NGA]

That's interesting. So surely others that have 'gutted' the 'secondary cats' would have seen that they are indeed just silencers?
And if so, no need to gut them and could remove the silencer box and replace with a straight-through section of pipe, as if they are not cats then not something a tester could complain about having been removed?

Which might explain the comments from those that have replaced these 'non-CATs' that the noise increases slightly but the emissions are unaffected.....

 

[ray d]

got it in today and I may have over done the mods a bit. It has increased the noise but I wish I done this first before I had a power flow exhaust system custom made for it. The wife has spoken volumes by saying nothing and just shaking her head. I will live with it for a while and see if the neighbors start giving me dirty looks. Spoke to MB today and it is a secondary cat which deals with any of the bad stuff the main cat does not "gobble up" On the up side you would not know it has been tampered with as no welds showing and took about an hour or so to fit using ramps (next project a 2 poster)

 

[brucemillar]

The wife has spoken volumes by saying nothing and just shaking her head.)

Okay. You have moved into very, very dangerous territory here. You may want to consider drastic man crawling, presents, romantic meals etc. Stay safe man watch your back.

Sent from my iPhone using sausage fingers.

 

[ray d]

Evening digging the hole deeper. Have put the pipe in the for sale section which has pleased her but I have not told her I have ordered 2 by-pass valves for it from power flow so I switch it on when I want it
There will be "hell to pay" the first time she hears it. but what can she do????
TAKE THE KEYS and my dinner will be in the dog for a few weeks.
Thank goodness she does not have my password for here

 

[Deleted member 37751]

Keep in mind that your exhaust will actually soften in sound slightly after a while from having the cats etc out, always sounds a lot louder at first.