The deletes you've done will not affect the emissions in the slightest. You'll either looking at a fueling issue/lambda sensor, or a failed CAT. As said above, looking at your readings, my experience would say the CAT is at fault. I would suggest you get someone to look at it for you and diagnose it. Remember you only have 10 working days for an MOT retest

This post on VWvortex backs up the fact that SAI, N112 and N249 delete will affect fuelling if they do not have resistors fitted.

 

http://forums.vwvortex.com/showthread.php?5378678-Car-running-rich-after-SAI-n249-n112-delete

 

So yes if you remove those systems and do not fit any suitable resistors your car will not be fuelling correctly.

 

I`m sure I read somewhere on here if you delete those systems and don`t put resistors in the ECU disables fuel trims and over time this obviously affects fuel/air ratios.

Edited 12 June, 201412 yr by sammyhale30

Passed Emissions with flying colours today!

CO emissions before fitting resistors to SAI, N112 and N249.  1.7

After fitting resistors CO emissions dropped right down to 0.1!!

 

I can safely say that anyone who decides to 'completely' remove the SAI, N112 and N249 must have resistors fitted for the car to run at its optimum and pass emissions tests.   I have a sneaky suspicion the removal of the N112(which controls the combi valve) had the biggest involvement with the over fuelling, as my last MOT I had the SAI removed but the N112 and N249 were still fitted and it passed fine.  We know that the N249 simply allows the ECU to control the opening of the Recirculation valve. 

 

Might be worth making this a sticky because it proves that without a doubt removal of these systems does affect fuelling, especially if the correct resistors are not fitted or the resistors are not fitted at all!

Edited 12 June, 201412 yr by sammyhale30

This is why bypassing the the N249 is easier. No resistors needed

I have to say I'm very surprised! The generated faults must have put the ecu in to some sort of safe mode perhaps?

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Well the car felt completely normal to drive!  You wouldn`t have known there was an issue without the emissions test.