If you can get to the EGR, remove and clean it with brake cleaner.

The EGR used to bring up the 'engine fault' light on my 2006 Fiesta 1.4 Tdci.. It became regular in hot weather, especially with stop-start driving. I bought a code reader - a Sealey VS8700 - just to check that the EGR was the problem every time the engine light came on. The light would always go out again, sometimes the next day, sometimes after a couple of days, or I could use the code reader to cancel the fault light. Eventually, I decided to try the 'diesel additive' remedy. After a year of regularly adding a mixture of 200:1 two-stroke oil and 1000:1 of Miller's Eco-Max or Diesel Rhino to every fill-up, the engine light very rarely if ever comes in now. And the exhaust doesn't smoke under load like it used to.

Many drivers of course wouldn't want the trouble of pouring in an additive every time they fill up. I make it easier by carrying a couple of used 250ml long-spouted fuel additive bottles as sold by all garages, which I have refilled with my own mixture. I have a mixing bottle at home marked with a line at 150ml for a 30litre fill-up. I pour in the cheapest two-stroke oil I can get, and that is from Morrisons, up to the 150ml line, then I get the diesel additive bottle - a Millers Eco-Max refilled from a bulk container, and squeeze 30ml into the marked dispenser. So what I'm doing is using the cheapest supermarket fuel and adding my own additive. The car has now done 217,500 miles.

Edited by MrEckerslikefromRamsbottom on 01/03/2018 at 13:02