Replacement Cat and back box

[Zspeed]

It appears by back road blasts are having a bad effect on my recently acquired roadster.

Previous owner stating that it been a good reliable car but it had only done about 5k in 5 years and my 2k in 3 months seems to be breaking a few things.

After getting a post cat o2 sensor eml recently and changing it the light came back in the first time I went down the back roads again.

I am cleaning maf so suggestion was I might have a blowing exhaust as I can tell it is louder. Put it on the ramp last night and got underneath to find the flexis blowing quite badly.

I have done a search but can't find anything recent on whether anyone thinks there is an aftermarket cat and back box that adds any power to the car.

Not looking for a sound, more if there is anything effective. The manifold has already been changed to a de cat.

I don't mind a slightly louder noise as I don't really do any motorway, it's virtually all 50-60 cruise or spirited drive.

Lightweight might be just as good as looking as power.

[The Other Stu]

Power? No. I mean, you can put a 200 CEL one on and it might have some initial help (and certainly more noise), but you'll be risking it on the MOT if your engine isn't in absolute harmony!

I have a 70k 1zz which burns absolutely no oil and always wizzed through the MOT. So I thought I'd give the Malian 200 CEL one a go. It failed. I'm told you need to get them stupidly hot to get them through - I didn't know this at the time.

The MR2 has a habit of "learning" (via the O2 sensors) and eventually sets the trims and so on right. It's very hard to add any extra power to the 1zz without spending a lot of money.

The go-to is the Cats2u one if you're after something cheap.

As for back box, again, stock is what it is. You could add more noise, but I'd be surprised if you got any extra power.
What does seem to help is a decat sports manifold - have you done this already? Toyosports or Malian ones are popular.

The bits in bold btw I'm confident of. The other stuff, is my personal opinion, but I'm not going to pretend I'm the bible on this stuff. YMMV.

[Iain]

I have just ordered a sports cat from zero exhausts. I had the same problem as you, flexis started blowing so was time for a new one.

I track my car so wanted a quality part and didnt fancy replacing the cat for non oem quality, which i why i paid for a proper one. They're quite expensive but will be worth it imo.

I looked at the malian one, but some not so good reviews put me off and they are just too cheap for what they are. The 200cel cat must be very low quality, if you buy a magnaflow cat on its own they are around £140, so a full pipe etc for £190 just doesnt wash.

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

[The Other Stu]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

[Zspeed]

I have just ordered a sports cat from zero exhausts. I had the same problem as you, flexis started blowing so was time for a new one.

I track my car so wanted a quality part and didnt fancy replacing the cat for non oem quality, which i why i paid for a proper one. They're quite expensive but will be worth it imo.

I looked at the malian one, but some not so good reviews put me off and they are just too cheap for what they are. The 200cel cat must be very low quality, if you buy a magnaflow cat on its own they are around £140, so a full pipe etc for £190 just doesnt wash.

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Thanks Iain, what sort of money did you pay for the Sports cat from zero?

[Zspeed]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

So sounds like I would be better sticking with oe. Had a suggestion of getting the flexis repaired. My cat looks good but the back box is very rough and already has a broken hanger hence why i though I might as well look at a system.

[Iain]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

I have no evidence no, just past knowledge of messing with many different cars for years.

Dont get me wrong, its not much power it frees up and i totally understand people who say it makes no difference, we all have our opinions.

But to me, a more free flowing exhaust, whether it be headers, sports cat or back box will release some power.

I felt the car had a tad more low-mid range power when i fitted the stainless manifold.

Not sure what you mean about the ecu learning, new to me that.

Also if there was no gains to be had, most of the runners in the mr2 championship are wasting there money.

I will be going on a dyno before long (just for giggles and ive never done it) so will see if theres any difference to be had, im interested to see the results.


@Zspeed the cat was £320.

[Ardent]

https://www.mr2roc.org/forum/index.php?topic=71464.0;topicseen

[Zspeed]

https://www.mr2roc.org/forum/index.php?topic=71464.0;topicseen

I cant see this, what isit?

[Iain]

Its a OEM back box for sale but you wont be able to view it until you reach 30 posts.

[Ardent]

@Zspeed

Sorry about that. Didn't spot the sub 30 posts

[Zspeed]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

I have no evidence no, just past knowledge of messing with many different cars for years.

Dont get me wrong, its not much power it frees up and i totally understand people who say it makes no difference, we all have our opinions.

But to me, a more free flowing exhaust, whether it be headers, sports cat or back box will release some power.

I felt the car had a tad more low-mid range power when i fitted the stainless manifold.

Not sure what you mean about the ecu learning, new to me that.

Also if there was no gains to be had, most of the runners in the mr2 championship are wasting there money.

I will be going on a dyno before long (just for giggles and ive never done it) so will see if theres any difference to be had, im interested to see the results.


@Zspeed the cat was £320.

I have seen the zero one now. Looks chunky, must flow easier. Have you had it long? Is it lasting? Seen a few comments now that aftermarket fonts last well.

What do they run in the championship cars?

[Zspeed]

@Zspeed

Sorry about that. Didn't spot the sub 30 posts

Getting there. No need to apologise. I do find it a bit strange but I assume it's calculated.

Would have thought anyone wanting to buy or sell on the forum would be welcome as it would benefit the members. If anyone was that way inclined they could simply drop a comment on a load of topics to get in quickly anyway.

[Zspeed]

Matt Lee has a Trd back box from his vm180 for sale. He wants a fair amount for it (£350)

Says it's a slightly fruitier set up with bigger pipes than standard.

It has lots of rust spots showing on it. I'm nervous that these are rusting through from inside as they have made on pattern on the box that makes it look like it might be the chambers. Therefore it might not last long for the price.

Has anyone had any experience of this? Is it best left alone?

[Iain]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

I have no evidence no, just past knowledge of messing with many different cars for years.

Dont get me wrong, its not much power it frees up and i totally understand people who say it makes no difference, we all have our opinions.

But to me, a more free flowing exhaust, whether it be headers, sports cat or back box will release some power.

I felt the car had a tad more low-mid range power when i fitted the stainless manifold.

Not sure what you mean about the ecu learning, new to me that.

Also if there was no gains to be had, most of the runners in the mr2 championship are wasting there money.

I will be going on a dyno before long (just for giggles and ive never done it) so will see if theres any difference to be had, im interested to see the results.


@Zspeed the cat was £320.

I have seen the zero one now. Looks chunky, must flow easier. Have you had it long? Is it lasting? Seen a few comments now that aftermarket fonts last well.

What do they run in the championship cars?

Its still on order, due in a couple of weeks. I have no doubt on the quality and that it will last. Kevin (from zero) only deals in quality 😃

Im unsure on the specifics or brands of what they run (most people like to keep quiet as to what they have, its very competitve) but i do know they change the manifold to get rid of the precats, either a 100 or 200 cel sports cat and normally some sort of custom, lightweight back box/muffler.

 

[Zspeed]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

I have no evidence no, just past knowledge of messing with many different cars for years.

Dont get me wrong, its not much power it frees up and i totally understand people who say it makes no difference, we all have our opinions.

But to me, a more free flowing exhaust, whether it be headers, sports cat or back box will release some power.

I felt the car had a tad more low-mid range power when i fitted the stainless manifold.

Not sure what you mean about the ecu learning, new to me that.

Also if there was no gains to be had, most of the runners in the mr2 championship are wasting there money.

I will be going on a dyno before long (just for giggles and ive never done it) so will see if theres any difference to be had, im interested to see the results.


@Zspeed the cat was £320.

I have seen the zero one now. Looks chunky, must flow easier. Have you had it long? Is it lasting? Seen a few comments now that aftermarket fonts last well.

What do they run in the championship cars?

Its still on order, due in a couple of weeks. I have no doubt on the quality and that it will last. Kevin (from zero) only deals in quality 😃

Im unsure on the specifics or brands of what they run (most people like to keep quiet as to what they have, its very competitve) but i do know they change the manifold to get rid of the precats, either a 100 or 200 cel sports cat and normally some sort of custom, lightweight back box/muffler.

 

Exciting, look forward to your review, especially if you are going dyno

[Ardent]

@Zspeed

Sorry about that. Didn't spot the sub 30 posts

 I do find it a bit strange but I assume it's calculated.

Definitely calculated.
I was here when the decision was made.
It must have served (still serving) it's purpose.
As I can't remember the reason it was brought in.
Discourage some fly by nights. I think.

[Zspeed]

Add in the slight power gains, less weight and more sound its a good buy.

Id like to change the back box but there are limited options and i may custom build my own in time.

Agree with your post about quality. The Cats2u one works and is fine for day-to-day, but top quality it's not.
Tomaky was telling me he had to replace his after 3 years.

With the bit in bold above though, do you have evidence? I can't see how you'd get it as we have a post-cat sensor which gets the ECU learning.

There's lots of noise on the forum that this mod or that mod adds extra power, but the only people documented running more than 140bhp on a NA 1zz have spent a lot of money getting it.

I have no evidence no, just past knowledge of messing with many different cars for years.

Dont get me wrong, its not much power it frees up and i totally understand people who say it makes no difference, we all have our opinions.

But to me, a more free flowing exhaust, whether it be headers, sports cat or back box will release some power.

I felt the car had a tad more low-mid range power when i fitted the stainless manifold.

Not sure what you mean about the ecu learning, new to me that.

Also if there was no gains to be had, most of the runners in the mr2 championship are wasting there money.

I will be going on a dyno before long (just for giggles and ive never done it) so will see if theres any difference to be had, im interested to see the results.


@Zspeed the cat was £320.

I have seen the zero one now. Looks chunky, must flow easier. Have you had it long? Is it lasting? Seen a few comments now that aftermarket fonts last well.

What do they run in the championship cars?

Its still on order, due in a couple of weeks. I have no doubt on the quality and that it will last. Kevin (from zero) only deals in quality 😃

Im unsure on the specifics or brands of what they run (most people like to keep quiet as to what they have, its very competitve) but i do know they change the manifold to get rid of the precats, either a 100 or 200 cel sports cat and normally some sort of custom, lightweight back box/muffler.

 

I have been chatting to someone today who has a zero cat on his car already. He highly rates it. He is on here somewhere as well.  Using it with a powerflow back box.  Believes it has made a difference.  Would be definitely be interested in your dyno results.  I have made an enquiry with them as well now.

[Ardent]

@Zspeed I believe @Mikeymead also has a zero and is very happy with it.

[Mikeymead]

@Zspeed I believe @Mikeymead also has a zero and is very happy with it.

Yes that's correct, Zero manifold and cat, the fit was spot on.

[Zspeed]

@Zspeed I believe @Mikeymead also has a zero and is very happy with it.

Yes that's correct, Zero manifold and cat, the fit was spot on.

I assume they make to order? Was the wait long?

[Mikeymead]

Yes they are made to order, I think it was about 3 weeks.

[Alex Knight]

Matt Lee has a Trd back box from his vm180 for sale. He wants a fair amount for it (£350)

Says it's a slightly fruitier set up with bigger pipes than standard.

It has lots of rust spots showing on it. I'm nervous that these are rusting through from inside as they have made on pattern on the box that makes it look like it might be the chambers. Therefore it might not last long for the price.

Has anyone had any experience of this? Is it best left alone?

I have a TRD backbox, check my RR thread.

[Zspeed]

Matt Lee has a Trd back box from his vm180 for sale. He wants a fair amount for it (£350)

Says it's a slightly fruitier set up with bigger pipes than standard.

It has lots of rust spots showing on it. I'm nervous that these are rusting through from inside as they have made on pattern on the box that makes it look like it might be the chambers. Therefore it might not last long for the price.

Has anyone had any experience of this? Is it best left alone?

I have a TRD backbox, check my RR thread.

That is some RR story. Got so far through and found the exhaust. I'm guessing you think it's worth the money then by the looks of what you paid?  As you know the item what do you think about the rust showing on Matts box. I'll get a picture and post it. I see some on yours but not as bad as this. I'm a little green so uncertain.  I have found a custom back box for £150 as well so paying £200 on top it would need to be very worth it.  Would prefer to put that in a pot for future 2zz, especially after reading you blog.

[Zspeed]

Here it is @Alex Knight .  To be fair the rest looks really good.