MOT Fail - Emissions (GGGRRRRR)

Justin.D · May 4, 2018, 18:17

As titled. Just been through the MOT and scored a big fat FAIL on emissions

CO is at 0.45% (Needs to be below 0.30%). All other tests are within range. Between me and the tester we tried all kinds of things to get it within range

Initially we replaced the sensors - no change

The thoughts now are the Cat - does this sound right?

Cats2u seems to be the cheapest replacement - I know cheapest isn't always best though

Anyone have any thoughts? Am I barking down the wrong tree? Anything else it's likely to be?

Thanks in advance

jonbill · May 4, 2018, 19:45

I think cat sounds likely and cats2u are fine. Many here have them.

Justin.D · May 4, 2018, 19:50

Quote from: jonbill on May 4, 2018, 19:45
I think cat sounds likely and cats2u are fine. Many here have them.

Thanks. I've just bitten the bullet and ordered one just before your reply. I'll probably decat the precats while I'm at it. I can't justify a Toyosport or Hamish manifold until I have a clean MOT (I know, I know, why do a job twice - truth is I've just spent £13k on a new daily drive and funds are currently a bit tight)

lamcote · May 8, 2018, 20:35

This is interesting:

https://m.smogtips.com/failed-high-carbon-monoxide-CO.cfm

shnazzle · May 8, 2018, 20:37

In our case it's almost always going to be air filter, maf or o2 sensor

Justin.D · May 9, 2018, 09:13

Quote from: shnazzle on May 8, 2018, 20:37
In our case it's almost always going to be air filter, maf or o2 sensor

Air filter is about 1500 miles old. MAF was cleaned a while back. Sensors replaced. MOT tester plugged in to OBD and checked readings. They were off a fair bit - the suggestion is the CAT being the next thing to change

New CAT is out for delivery today. Fingers crossed this time (Although I won't have chance to fit it until tomorrow)

shnazzle · May 9, 2018, 10:06

Yup. If all else checks out, that thar cat not be purrin' no mo

Ozzy · May 9, 2018, 11:15

Quote from: Justin.D on May 4, 2018, 18:17
Cats2u seems to be the cheapest replacement - I know cheapest isn't always best though

Anyone have any thoughts? Am I barking down the wrong tree? Anything else it's likely to be?

Thanks in advance

That will be perfectly fine, it's a direct replacement. I'd get new exhaust gaskets and rings just to be on safe side so it doesn't develop a leak. Should only be £20.

I personally think its waaay better than stock. Not sure if this is more like a sports cat or stock?? Doesnt cause an EML to go off so thats good.

It seems much stronger, waaay lighter and not as bulky so less chance of hitting the floor. Also gave my car some significantly noticable more power and better throttle response so can't complain. Mechanic who was testing my car was suprised at the difference as well... Been 3 months and no problems soo far

Justin.D · May 9, 2018, 15:12

Quote from: ossy on May 9, 2018, 11:15
Quote from: Justin.D on May 4, 2018, 18:17
Cats2u seems to be the cheapest replacement - I know cheapest isn't always best though

Anyone have any thoughts? Am I barking down the wrong tree? Anything else it's likely to be?

Thanks in advance
I'd get new exhaust gaskets and rings just to be on safe side so it doesn't develop a leak. Should only be £20.

Yep, got them. They were bundled in the deal with the cat. Just shy of £140 delivered with the fitting kit. Arrived earlier, just got to find time to fit it now (Hopefully tomorrow)

Thanks folks

Justin.D · May 10, 2018, 07:45

Moving on - A bit more advice needed

I've managed to get the 3 amigo's off - quite easily really - that plusgas, wd40 and German penetrant mix made light work of it

The next issue is separating the cat from the manifold. It just won't budge. Any words of wisdom for this? I can't get the hammer out yet as it's still early. Is there a gasket in between the 2 parts? Should I just give it a big 'heave ho' and put all my weight in wiggling it loose? Any other secrets I need to know?

Thanks again folks. I'm determined to do this myself and hopefully get back to the MOT place before my free retest runs out

Justin.D · May 10, 2018, 08:16

It's ok - Panic over. Just been out to have another look. I must have stared at it wrong as it 'just fell off' - honest!!!

Off to work for a couple of hours, hopefully get the new one fitted this afternoon

If I manage this successfully I promise to upload an avatar

paulj · May 10, 2018, 08:45

It's normally the O2 sensors which get scared and fail if you look at them. You've done well to spook the whole thing!

shnazzle · May 10, 2018, 09:03

Surprised. I have the opposite problem most of the time. I've taken the cat off an mr2 at least 10 times and I think I have a 50% hit rate between cat and my head as it drops off

Justin.D · May 10, 2018, 16:48

Fitted. PASSED with flying colours. Happy days again. Now, time to create an avatar

Carolyn · May 10, 2018, 18:10

So pleased.

Looks like the original cats are all coming to the end of useful life.

shnazzle · May 10, 2018, 18:12

Quote from: Carolyn on May 10, 2018, 18:10
So pleased.

Looks like the original cats are all coming to the end of useful life.

I was just saying this to Helen. It seems a few components on our cars are hitting end of life about now.
I bet power steering pumps won't be far behind. Then timing chains.

Justin.D · May 10, 2018, 18:15

I did take one picture of the whole process - I'm not really one for documenting everything in photo form

At least I am now rid of the rattly heatshields too!!!

Justin.D · May 10, 2018, 18:16

Quote from: shnazzle on May 10, 2018, 18:12
Quote from: Carolyn on May 10, 2018, 18:10
So pleased.

Looks like the original cats are all coming to the end of useful life.
I was just saying this to Helen. It seems a few components on our cars are hitting end of life about now.
I bet power steering pumps won't be far behind. Then timing chains.

Crikey, don't say that. I wouldn't have a clue where to start with the DIY fix