MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: CB 1971 on May 10, 2021, 20:36

Title: Exhaust blowing
Post by: CB 1971 on May 10, 2021, 20:36
hi all,
Last couple of weeks noticed exhaust blowing got original toyota manifold and original toyota cat  pipe,pre cats were removed years ago ,had a look and can't find where its blowing are the original cat pipes known to corrode,another question if I replace with  de cat pipe am I going to  run into problems mot time,
Title: Re: Exhaust blowing
Post by: shnazzle on May 10, 2021, 20:57
Quote from: CB 1971 on May 10, 2021, 20:36hi all,
Last couple of weeks noticed exhaust blowing got original toyota manifold and original toyota cat  pipe,pre cats were removed years ago ,had a look and can't find where its blowing are the original cat pipes known to corrode,another question if I replace with  de cat pipe am I going to  run into problems mot time,
Flexis are easy enough to get fixed as they're cheap.

Decat pipe will most definitely cause MOT issues.

Cats2u make a cost-effective full cat replacement that fits well and does the trick.
Title: Re: Exhaust blowing
Post by: 1979scotte on May 10, 2021, 21:17
De cat just isn't worth the hassle imho.
Title: Re: Exhaust blowing
Post by: Iain on May 10, 2021, 21:20
Quote from: CB 1971 on May 10, 2021, 20:36hi all,
Last couple of weeks noticed exhaust blowing got original toyota manifold and original toyota cat  pipe,pre cats were removed years ago ,had a look and can't find where its blowing are the original cat pipes known to corrode,another question if I replace with  de cat pipe am I going to  run into problems mot time,

Would stay away from the decat pipe. Will cause problems come mot, and also no doubt throw up a error code as the post-cat sensor wont be reading correctly. A few have had success tricking the sensor but not worth the hassle in my opinion.
Title: Re: Exhaust blowing
Post by: shnazzle on May 10, 2021, 21:29
Agreed. I'd go for a 400cell cat if I had to do it again, and I've got a 200cell, not even a decat. 
Stock is 800cell I think?
Title: Re: Exhaust blowing
Post by: 1979scotte on May 10, 2021, 21:37
Quote from: shnazzle on May 10, 2021, 21:29Agreed. I'd go for a 400cell cat if I had to do it again, and I've got a 200cell, not even a decat.
Stock is 800cell I think?

If I was Na and stock motor I'd go 800 cell.
I don't believe I would notice the extra 1.5hp or whatever you'd gain.
Title: Re: Exhaust blowing
Post by: CB 1971 on May 11, 2021, 20:19
do I need a type approved cat whats the difference?
Title: Re: Exhaust blowing
Post by: 1979scotte on May 11, 2021, 21:09
Quote from: CB 1971 on May 11, 2021, 20:19do I need a type approved cat whats the difference?

Technically yes but I don't think I've ever heard anyone have issues if it's not.
Title: Re: Exhaust blowing
Post by: shnazzle on May 11, 2021, 21:28
Quote from: 1979scotte on May 11, 2021, 21:09
Quote from: CB 1971 on May 11, 2021, 20:19do I need a type approved cat whats the difference?

Technically yes but I don't think I've ever heard anyone have issues if it's not.
Chances are it'll be stolen off your car anyway :)

Rat bastards...

But as Scotte says; genuinely never even hears anything anecdotal about issues with an aftermarket cat. Nobody has the time/money to verify whether a cat was 100% the right type. Not even sure there are rules to specify that.