Emission problems

[dave wall]

I've got a 3.2 2006 Boxster S which has just failed its MOT due to emissions.
It is only just over the maximum allowed. I have had the front cats removed over 3 years ago and there has never been a problem with the MOT up to now.
I've given it a good thrash to try and clear it plus I've had it carbon cleaned and also used some injector cleaner additives but the figure will not come down at all.
I then took it to a local specialist who has looked all over the exhaust for leaks and plugged it in to the diagnostics but they say there is nothing wrong with it.
I've read that a service could help so I'm getting this done at the weekend.
Has anyone got any ideas of how to help sort it without having to buy 2 new headers.

TIA
Dave

[Porsche911R]

well the cars not legal so a tricky one.

[dave wall]

The car was legal as it has passed all previous MOTs with the catless headers fitted
I was wondering if there was anything else I should look before changing them

[cslwannabe]

I assume it had decent fuel in the tank - fresh, not 6 months old... Had it always been marginal previously on emissions?

[gsewell]

Emissions are tightening up every year, so the fact it passed last year is irrelevant.

[cslwannabe]

Really? They’ve lowered the limits for existing petrol cars?