MR2 Owners Club

Hey all,

Have a question with regards to catalytic converters...

I tried searching but couldn't find any solid info before I spend a load of cash on a replacement cat. Hopefully someone can advise.

Have a sw20 rev 5 n/a, 1mz conversion. Modified y pipes into standard rear section on mr2 exhaust

Currently doing a s54 to e153 swap, and will be creating a build thread at some point from as long ago as I can find pics for.

Q. I need to replace the cat. Can I use the cat for the na/turbo mr2? Or do I need a cat suitable for the 1mz? Are all cats pretty much the same?

It's a 1999 so not cat exempt.

Thanks in advance!

I would say that you would be better off using a mr2 cat. Given the swap has been made to suit the mr2 back box. I run a 3vz-fe turbo in a jdm rev 1. So no cat or silencer for that matter. But the mr2 cat should do the job fine for the emissions. Can you not borrow one to fit just for the MOT?

Thanks buddy

That's what i was hoping, that I can use the mr2's cat and pass emissions.

When I fit the new backbox (think it's a fox racing one) I had to find a new cat and bought a cheap BM catalysts one - for the last couple of years the MOT garage i used have been very "kind" to me.

The old cat and backbox are gone, unfortunately.

Unfortunately I can't use that garage anymore hence looking for replacement. I guess i'll find a type approved one as the one i bought (non type approved) didn't seem to do much in the way of lowering emissions - assuming the engine is running right of course!

Your's is looking a lovely thing.

Thanks for your advice previously about turbo/na driveshafts - ended up getting some custom shafts that come with n/a hub splines and e153 gearbox splines been collating all of my picture over the last 3+ years and going to creat a thread soon to document before I forget everything haha

added a few pics on here anyway, of the derusting last year, the exhaust setup etc

Thanks been an on going project for some years.
Where did you get the shafts made/from

Yup, had mine for about 7 years now maybe longer! indefinate project.

I got these shafts: https://mr2heaven.com/products/mr2heave ... 6687794344

2 Full Complete E153 HYBRID Axles (2x Half shafts With 2x Stubs)

They look well made and good quality, not cheap though - but cheaper/easier than sourcing turbo hubs!

Ah right. The stuff from there is very good quality. You can also check out frankensteinworks along side woodsport for some funky v6 bits.

had "standard" NA cat on my 3VZfe when 1st converted until I found that it didnt need one being a 92 engine in my Rev5.
for the 15 months and 2 MOTs it ran fine and passed emissions with ease.
if you are building a new exhaust with Y pipe (had one on mine coupled to NA back end) you could go with sports free flow cat. diff sizes so you get one that you need to fit the custom exhaust.

Well, just had the mot with new cat and turns out overall HC and CO reading came back in spec, just lambda reading was a bit high but theres a leak on the manifold which i'll be replacing soon so probably that!

Would love to build a new exhaust pipe when cash, instead of the pipe flowing back on itself