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The mkiv Supra Owners Club

1 Cat = No Restrictor Ring


Neil_M

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Folks,

 

Just a quick query as it has been covered slightly before. Im really after confirmation...

 

If I remove one cat, will it be ok for MOT emissions (assuming everything else is ok)? Also with the single cat, will it be safe without using a restrictor ring? Or is a restrictor wise to use just in case?

 

Bare in mind im thinking of going for the HKS Titanum Racing Zorst, I assume this doesnt remove the second cat. I believe its cat back? So ill need a decat pipe to remove the second cat, leaving the first in place.

 

Also on a note regarding the cats. Has anyone just bored and ripped out the standard cats as an alternative to buying a decat pipe?

 

Many thanks,

Neil

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removing the 2nd cat and leaving first one in you should be fine with emmissions as long as the cat 1st is not shagged.

 

Leaving the 1st cat in you will not need any other gadgets ie fcd or restrictor ring ( if j spec) as the 1st cat is the most restrictive so will not over boost.

 

the zorst goes up to the 2 nd cat and you will need topurchase one of someone

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jamesmark - thanks for the reply...

 

What about removing the first cat and keeping the second?

 

Will this be a better solution in terms of reducing the restriction as a well as keeping the emissions above board?

 

BTW this would be for a JDM Sup...

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You can leave either cat in to restrict boost however cats = heat and heat = bad.

 

This is why a restrictor plate between the second decat pipe and the cat back system is a better option.

 

Personally I'd move the heat away from the turbo's as much as possible which means I'd remove the 1st cat if I

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