Hi Flow Cat

[bodrobot]

Hello,

Am waiting for january to put on my replacement manifold, my car's emission are through the roof.

I've also got eml's on due to the hi flow cat i have on their now.

So i'm gonna replace the cat, now will a new high flow cat enable me to pass an MOT?

Or should i get a normal cat?

If i can pass an MOT with a hi flo 1 i will get a new one put on, (the one on thier is just over a year old!).

And i know i could just decat it but i cannot be asked to have to chop and change it.

Thanks

[nrgizerbunny]

Hello,

Am waiting for january to put on my replacement manifold, my car's emission are through the roof.

I've also got eml's on due to the hi flow cat i have on their now.

So i'm gonna replace the cat, now will a new high flow cat enable me to pass an MOT?

Or should i get a normal cat?

If i can pass an MOT with a hi flo 1 i will get a new one put on, (the one on thier is just over a year old!).

And i know i could just decat it but i cannot be asked to have to chop and change it.

Thanks

It's usually dependent on how many cells the cat has. I would go down the chop and change route if it was me. For the sake of an hour it takes to go from a decat to a cat, it's worth it. There is no cat that is as good as a decat, hiflow or not.

[bodrobot]

Would doing chop and change require me to remap to stop eml light coming on?

I.e when i decat it i would have to remap and again when i change to the cat for the MOT?

[nrgizerbunny]

An O2 defeat would do the job, no need for a remap.

There are two options for that, either space the sensor out or electronically defeat it.

I have never tried the spacing out of the sensor but I've done the electronic defeat, you need a sine wave 0.7v every 2-3 seconds frequency.

[bodrobot]

An O2 defeat would do the job, no need for a remap.

There are two options for that, either space the sensor out or electronically defeat it.

I have never tried the spacing out of the sensor but I've done the electronic defeat, you need a sine wave 0.7v every 2-3 seconds frequency.

How would i go about doing this???

[nrgizerbunny]

You'll need to make an O2 simulator circuit or buy one.

The Corolla one is not the easiest one in the world to defeat electronically. I tried all of the diagrams on the internet and they were rubbish so I got my own.

I believe hangar11 sell them but again, you need a multimeter to set. Or buy it and then get someone else to set it for you.

[bodrobot]

I'm being a pain now, hangar11? Have googled it and it just comes up with collection of WWII planes?

I'm guessing i would just have to kinda set up the wave pattern and frequency and wire it in to the sensors before and after the cat?

[msprince]

Ive got the spacer in mine to stop the eml, works perfect, I think it cost bout a tenner.

Im with ngr on this decatting makes such a difference.

[nrgizerbunny]

http://www.hangar111.com/

sorry I missed a "1" off.

[bodrobot]

Ive got the spacer in mine to stop the eml, works perfect, I think it cost bout a tenner.

Im with ngr on this decatting makes such a difference.

Where do you put the spacer?

[nrgizerbunny]

between the lambda sensor and the exhaust.

[CorollaD4D]

do what any car enthusiast should do. get to know your mot tester well. you may find he won't pick up on things like em lights for decat ;)

[nrgizerbunny]

The problem is, if you decat the car, the ECU might stick itself into limp mode. So less power than you had before.

[sheepscloth]

Check this link from poland( and newcelica.org) apparently a simple RC circuit is enough to fool the ECU!

http://www.forum.corollaclub.org/viewtopic.php?t=27423&start=3675&sid=132d3e4d35a42d39a3f2170b2b267c18

1uF cap and 1M resistor.

NRGIZER: have you tried this one?

[bodrobot]

Well my EML has been on and off since i've had it due to the cat and it has never gone into limp mode. A cat shouldn't perish and not function corrrectly after just 1 year should it?

It makes me think hiflo cats are pointless because obviously u only have one so u can pass an MOT otherwise u'd decat!

Thanks for all your help. Just got to wait until after xmas so i can start spending on my car instead of my family :)

[msprince]

No it shoudnt but neat fuel will kill a cat, your em light pn is prob down to the high flow cat.

A nomal cat is around 400 cells, a sports cat can be anything below 400 cells, around 200 cells should pass an mot (depending on maufacture, structure etc).

[nrgizerbunny]

Check this link from poland( and newcelica.org) apparently a simple RC circuit is enough to fool the ECU!

http://www.forum.corollaclub.org/viewtopic.php?t=27423&start=3675&sid=132d3e4d35a42d39a3f2170b2b267c18

1uF cap and 1M resistor.

NRGIZER: have you tried this one?

Yep, didn't work.

[bodrobot]

You can read polish as well????

I have been told a remap would turn the light off. Is this true? And would it enable me to pass an MOT?

[mr-p]

a remap is really the best way to go about it but trying to find someone that can map the standard ecu is the problem! just a remap wont enable it to pass the mot though as it will still fail on the emission test without a cat. you can pass the emission test without a cat but you have to seriously nail it to high revs instead of sitting at around 3000rpm, some of the high flow cats are good some not so good lol all depends which one was on your car but they can and will fail after a year if it was a not so good one its just like buying a non oe cat half the price but half the life span . both the other ways of getting rid of the eml do work tough, best off doing what nrgizer said and just swap them over when its test time. what i did on ny zs never got a problem with it going into limp home mode, just stick some tape over the light

[sheepscloth]

Check this link from poland( and newcelica.org) apparently a simple RC circuit is enough to fool the ECU!

http://www.forum.corollaclub.org/viewtopic.php?t=27423&start=3675&sid=132d3e4d35a42d39a3f2170b2b267c18

1uF cap and 1M resistor.

NRGIZER: have you tried this one?

Yep, didn't work.

Thanks Buddy. Then I won't waste my time trying.

Guess there is no other way than the full simulator solution.

Cheers

[nrgizerbunny]

Check this link from poland( and newcelica.org) apparently a simple RC circuit is enough to fool the ECU!

http://www.forum.corollaclub.org/viewtopic.php?t=27423&start=3675&sid=132d3e4d35a42d39a3f2170b2b267c18

1uF cap and 1M resistor.

NRGIZER: have you tried this one?

Yep, didn't work.

Thanks Buddy. Then I won't waste my time trying.

Guess there is no other way than the full simulator solution.

Cheers

The problem is every car is ever so slightly different and the tolerances on components are pretty big, you need something that you can adjust to cope with the tolerances or build it specific to the car.

If you have an oscilloscope it is much easier - less trial and error.

[sheepscloth]

Check this link from poland( and newcelica.org) apparently a simple RC circuit is enough to fool the ECU!

http://www.forum.corollaclub.org/viewtopic.php?t=27423&start=3675&sid=132d3e4d35a42d39a3f2170b2b267c18

1uF cap and 1M resistor.

NRGIZER: have you tried this one?

Yep, didn't work.

Thanks Buddy. Then I won't waste my time trying.

Guess there is no other way than the full simulator solution.

Cheers

The problem is every car is ever so slightly different and the tolerances on components are pretty big, you need something that you can adjust to cope with the tolerances or build it specific to the car.

If you have an oscilloscope it is much easier - less trial and error.

OK, had hoped there would be a standard solution, and that you could share your circuit and component values. But if every car varies as you say then I guess I have to get the oscilloscope on.

sorry to keep banging on this issue.

[nrgizerbunny]

The voltage you want is 0.6v max about 0.2v min, with a cycle every 2.5 seconds.

Just need a circuit to do that. You'll find something stupid like the heater circuit voltage will mean you having to put trim components etc in.