2008 A3 1.4 TFSI failed emissions miserably please help

[Bowen]

Hi guys hope somebody can help as at a bit of a loss. I have an A3 2008 1.4 tfsi T I have just done a full timing chain kit on her including water pump as I had a Coalition issue between crank and cam, timing chain tensioner was ruined so slack chain all replaced nicely with nes bolts gaskets and oil seals but taken for mot 2day and failed miserably on emissions. Replaced flexible exhaust as was leaking and hoped would solve it but no such luck! Any ideas on why it would be so high ? Any help greatly appreciated. 

Thanks Nathan 

[Bowen]

Iv also fitted a cold feed induction kit to it but as its not metered didn't think would cause the issue 

[cliffcoggin]

3% carbon monoxide is extraordinarily high. What was the CO level before you changed the induction system?

The engine is getting on a bit at 175000 miles. What is the oil consumption? Does it smoke? Does it still have a functional EGR valve? Has the engine been modified in other ways?

[Bowen]

Hia cliff thanks for the reply..

These are the readouts from the tests. First was the initial fail, changed flexi exhaust pipe and other failure bits. Took back to check emissions and scraped though but wasn't a test just checking the exhaust was the issue! Had a corilation problem with crank and cam, fitted new cam sensor but still same (chain was loose as tensioner was shot) new chain kit, water pump etc fitted, new oil and filter but still miles of on emissions. 

[Bowen]

There is a slight oil leak on the crank seal pully side, doesn't use much oil normally probably half a ltr over a year. No smoke out the exhaust and runs lovely. 

After I took it back to check emissions and it passed I fitted a cone filter and new cam sensor then between that and going in for the actual retest the engine management light came on which was solved by the new timing chain but emissions still the same. Any ideas or theories welcomed 

[Bowen]

It does struggle to start after fitting cam sensor and cone filter now tho dont know if its worth trying old cam sensor back on it and air box back on ? 

[Bowen]

Only thing done to the car is a stage 1 map blow of valve and now induction kit 

[cliffcoggin]

The low oil consumption suggests the engine is in reasonable condition for its age, and in standard form would likely not have high CO emissions. Therefore I'd say your modifications are responsible for the problem, and the solution is to restore the engine to standard form.

[Magnet]

Hello Nathan from the Homeland,

It might be me, but I’m a bit confused with the timeline on this. By what I can see, it fails on the 6th March, passes on 12th (just, but OK it passes), then fails again on another test on 20th March - why another test. 
You say the exhaust was leaking ( and this would certainly be a contributor to the high CO), but it’s difficult to get my head around why you would have presented it for an MOT with a leaking exhaust. 
The high HC is another worry, and I notice you have changed the oil, which is good. Plugs and plug gaps? 
A couple of questions Nathan:- 

How long have you owned the car, and if not long, did it come to you as a ‘project’? If you have had it some time, what has been the MOT history situation over the last couple of years? Does it have its original Cat? Aftermarket Cats. can often result in barely limping emission tests. 
Are you sure, the valve timing is spot on? I guess you are. 
If this were mine, I would be returning the whole thing back to ‘stock’ and going from there. 
Kind regards,

Gareth.