Emmissions MOT failure

I am informed that the cause of the high emissions from my R reg Symphony is the new fuel being left in the engine for a number of months. Is this likely to be the case? What do I need to do to reduce the emission reading?

I would find a good fast road and drive it in 3rd gear and 3000 revs for a good 20 miles, and get it good and hot before  you take it for MOT , hopefully that will clear injectors.

I agree with Paul.  When my mechanic opened his own MOT station he had a few vehicles which were failing on emissions.  When he raised this an 'old' tester he knew he was told tell owners to take their vehicles for a right good run before the test as it needs to be right up at running temperature to give correct readings.

Thanks for your replies. I was advised to do as you suggest and to use an additive. However the Mot tester stated that my emissions were so high that the action did not work. A suggestion made to me was that the seals in the engine had been eroded by the new fuel. But to find out which seal(s) I needed a detailed emission reading. Two test stations said that they could not provide a detailed emission reading due to the level of emissions likely damaging there test equipment.

Also worth considering running with additives or a tankful of premium fuel for a few weeks before the MOT is due.

lots of the talk here sounds a good help BUT
start with the basics first
1 air filter is it clean
the seals that was said ? valve stem oil seals ? are you using oil
fuel pumps on older vehicles have problems as fuel had more lubrication in it years ago so helped lube the pumps
a picture as to the readings may help

To a certain extent it will depend on what engine you have - fuel stored in the tank "for a few months" is more likely to affect a petrol engine than a diesel. But TBH if it's been only a few months, I doubt it's that. I guess it's fair to assume that an R reg Boxer is fuel injected.

If the emissions are as high as they suggest then I'd want to be sure that the air and fuel filters have been changed within living memory, and then it's ~probably~ going to be down to a faulty sensor somewhere if it's drastically overfuelling. Temperature, MAF, fuel pressure - it could be any of those.

Fuel "sitting" would very unlikely be the cause here. We've had farm equipment sit ideal for years that fire up and run "clean". As suggested in other posts, I'd be looking at filters for this issue.

A 1992 diesel van I once owned failed on emissions on the first year that it was an MoT requirement. I did all the steps suggested and the van just scraped through for a few years. I ended up cutting my losses and selling it with a full 12 months MoT.
The irony is your van will be a historic vehicle in 15 years or so, and being free of MoT requirements, can belch out as much pollutants as you like...
Al.

If this engine has a carburetor it might be that the higher % of ethanol in modern fuel has damaged some of the components within the carburetor. 

Can you find someone who rebuilds carburetors (should be a few now with the interest in classic cars) and get them to take a look at it?

The OP hasn't exactly been forthcoming with information, so maybe we'll never hear anything from them about this again. So we still don't know if it's petrol or diesel.

But as far as I can see, the base vehicle dates from around 1998, when carburettors would have been rare. As far as I can see, all Peugeot Boxers from 1993 onward were fuel-injected, whether petrol or diesel.

That itself doesn't mean that a reaction to the higher ethanol content can't have happened, though from personal experience (owning both a 1960's and a 1980's car) the likelihood of damage does seem to be a bit less than some people predicted.