MOT emissions fail!

[AndrewT1983]

Hi all

This is my first forum post, so apologies it's a whinging cry for help lol.

Just got the below back from the MOT test. Looks to me like the cat is hollow (is non standard for sure but not taken it off to check).

Anyone have any thoughts or ideas how to get it through the test??

Thanks in advance

Andrew

 

[AndrewT1983]

 

[AndrewT1983]

 

[Crybert]

Did the mot station not suggest anything or quote a job to get it through?

 

[AndrewT1983]

Wow quick reply.

All they suggested was a new cat and two new sensors at a discounted price of £530 plus fitting. Just a local kwik fit though so expectations were low going in.

I replaced the post cat sensor prior to the test and the car runs just fine so assuming the pre cat sensor is fine too.

 

[Crybert]

What about buying a second hand cat from here? Someone breaking a car will have one. Much much much cheaper than £530

 

[AndrewT1983]

Yeah that was my first thought. Typically can't see any in the parts for sale section at the moment but will keep a look out.

Just wanted to check in case anyone else has a similar issue and it was something else.

 

[Crybert]

Just ask someone breaking a full car if they have one

 

[cs_dave]

Sports cat any use to you?

 

[AndrewT1983]

Dave, it will be if it'll fit? Got a standard manifold and a Scorpion SRN019 cat back.

 

[bloke]

Can't see pic properly on phone bit looks like they just need to take their time to get lambda down before they actually start the timer for test.

 

[spanky2000]

Hi, what mileage is on it? I had similar issues recently but it wasnt the cat. The hcs disappeared when I put some Lucas Heavy Duty Oil Stabiliser in and the lean lambda reading which was 1.07 on mine dropped to 1.02 (pass) when I pasted up two small holes around a weld on the post cat silencer. I think the 172 has a 400 cell cat but the 182 uses a 200 cell cat.

 

[AndrewT1983]

Currently on 111k. The centre exhaust mount was toast so could be some cracks around there too I guess. Will check it out. I've run some redex through recently to clean the fuel system but not serviced it yet so oil is unknown quantity.

 

[spanky2000]

Hi sorry misread the pic. Thought it was high hcs. Bit confused. Id always thought high co was because of rich mix but lambda implies lean mix. Lookin into to this for sure!

 

[AndrewT1983]

Hi chaps, quick update. Based on feedback here copious Googling I got hold of a standard cat from the classifieds, put in a little Lucas stop leak, and used a crap load of sealant to be sure there were no air leaks around the lambda sensors.

Just waiting for the restest to be done, so will let you all know how it goes.

Incidentally, the cat I had on wasn't hollow but the structure inside was much coarser than the standard one, and about half as much in length. on the plus side the exhaust is much quieter, but I do seem to have lost a little at the top end. Am surprised it was so noticeable. Throttle response a little dulled too. Might be putting it back on if the car passes....

 

[AndrewT1983]

Phew, passed. Advisory on track rod ball joint but emissions were peachy.

Thanks all for the advice, justified the forum membership fee several hundred times over.