Maximum fine for motoring offences concerning the condition of your vehicle are Level 4 (£2500). Actual fines are likely to be Band B (100% of your net weekly income), more for a driver driving for business, more again for owner/driver on business. Also mandatory 3 penalty points. If you have one or more previous offence of a similar nature in the past 3 years, it’s a mandatory minimum 6 months disqualification. Contribution to CPS costs and victim surcharge on top of the fine.

What is the indication that EGR is blanked off ?

Do remember that they don't let us Yanks play with diesels but I have read a bunch about them here.

There's probably a Delta Pressure setup between the exhaust flow upstream of the EGR pipe and below. If there isn't enough difference in those pressures you'll likely get a CEL (USA carspeak for Check Engine Light).

The "14mm hole" in any plate you fashion will allow enough gas to pass through to satisfy the check software.

Visually, an inspector might see the plate sandwiched between the stock parts.
Do remember, these inspectors are trained and they've seen this jazz before.
It's a case where they don't have to be as smart as you...they have experience.

I'd love to see the expression on a caught offender's face. That goes for either side of the Atlantic.

Also remember, they may use a sampling statistic, say, every 5th car, to disassemble to inspect. This is when I'd expect an offender to be hit with the MAX FINE. Max Fine isn't the tailor down the street. Max sets your fun budget back 3 years. Just sayin'.

Catalytic converters were introduced here well before OBD testing. Removing said converters and replacing them with a run of plain exhaust pipe was said to be common. The offender would sell his removed converter for a princely sum.

The authorities required garages to visually inspect for converters' presence and report.
As a subsequence you saw "No test tubes" signs at service stations. NOBODY wanted to be anywhere near the big fine.
The garage owners surely didn't want to be the rat; even if required by law.

And no, the lie, "I was tuning my engine and needed to run it without pollution controls temporarily", didn't fly.

That sounds like the Californian approach, MOT inspectors in the UK aren't allowed to do any dismantling whatsoever.

If emissions control equipment has been obviously modified or is missing it's an MOT fail.

It's becoming more socially unacceptable to tamper with EGRs and DPFs as air quality gets more media attention and more people know someone with a health issue etc. I guess we are lucky that our EGR and DPFs on the D5s are very reliable indeed.

As well as being downright illegal

Tampering with emissions systems is illegal in most countries in the world.

this guy probably rings his insurance company to declare the winter tyres

Do you not then?

I don't run winter tyres.

I had a set once that had no grip in the rain.

Anyone needed to replace EGR gasket before?
 

Mine has a split, looks like this
Attachment 128906

This gasket is from where the valve actuator attaches to the egr valve cooler.

What is it called? / what is the part number?

Where is best to buy them from? I’d prefer genuine Volvo

That's the servo - EGR seal, part number 8653136, although you've probably already sorted it by now. Posting just in case it's useful to someone else.