Pre-cat delete + sports cat = MOT headache?

tomislavp4

Paid Member
So one of my cats is done and the garage thinks it's probably the pre-cat but it may be both. So I was thinking of replacing them both, to be sure.

I have already ordered a KTR sports cat and was thinking of ordering a Toyosport exhaust manifold but now I wonder if having no pre-cat and only 200 cell main cat will lead to the car not passing MOT (well, the Swedish equivalent really). Anyone with experience on this?

I really don't want to buy OEM manifold because it will cost 1/4 of what the car itself is worth.
 

Sean197

RIP Albi :( Hello Red 200 :)
Moderator
mine passed the MOT with a sports cat, although it was a megane engine. You could always gut the insides of the pre-cat and leave the manifold in place, but in terms of emissions a sports cat will be fine for the MOT.
 

tomislavp4

Paid Member
mine passed the MOT with a sports cat, although it was a megane engine. You could always gut the insides of the pre-cat and leave the manifold in place, but in terms of emissions a sports cat will be fine for the MOT.
Ok, so it passed with no pre-cat, sports cat only?
Gutting the pre-cat is something I didn't think of actually, thank you.
 

Sean197

RIP Albi :( Hello Red 200 :)
Moderator
Ok, so it passed with no pre-cat, sports cat only?
Gutting the pre-cat is something I didn't think of actually, thank you.
I think the cup racers ran with a standard manifold with the pre-cat gutted, but I might be wrong.

Actually, I just remembered before my megane engine went in mine passed with a toyosports manifold and the standard cat, so a sports cat should be ok. The lack of pre-cat certainly wasn't an issue in terms of it not being there (visual inspection).
 

tomislavp4

Paid Member
I think the cup racers ran with a standard manifold with the pre-cat gutted, but I might be wrong.

Actually, I just remembered before my megane engine went in mine passed with a toyosports manifold and the standard cat, so a sports cat should be ok. The lack of pre-cat certainly wasn't an issue in terms of it not being there (visual inspection).
Alright, thank you. I'm assuming UK MOT and the Swedish one have the same limits on emissions so if it's good over there, there should be no problems over here either. I hope my assumption is correct.
 

vfdesignz

Gold Member
Mine passed TÜV in Germany with the KTR manifold and the standard main cat. Just have get some heat in the standard main cat to get it working. Should be the same as with a Sport cat.

And the stock main cat is 200 cell too
 

tomislavp4

Paid Member
Mine passed TÜV in Germany with the KTR manifold and the standard main cat. Just have get some heat in the standard main cat to get it working. Should be the same as with a Sport cat.

And the stock main cat is 200 cell too
Ok, should be fine then. Thank you.
Didn't know the standard one was also a 200 cell unit. So basically replacing the stock one, if it's working fine, with a "sports" cat is meaningless, the airflow through it would be the same as the stock one?
 

vfdesignz

Gold Member
That‘s a good question :smiley: I think so? I know a guy who runs a R3 Manifold with I think a 200cell HJS Sportcat and he is happy with that Setup.

Just remember to get some Heat to pass the MOT. I did 2-3 vmax runs and passed it without any problem. :smiley: