I have a year-old Kodiaq 190TSi with this petrol particulate filter thingy, which is a first for me.

 

I primarily drive 20-minute journeys, which are about 8 miles; my car is just under 10,000 miles from new.

 

At the end of the journey, a couple of times recently, when turning off and opening the driver's door, the car sounded hot. You heard crackling, for want of a better word, which sounded like something hot was cooling and contracting.

 

Friday morning, it smelt hot and did 22mpg, whereas usually, it would be 36mpg for my journey to work with no traffic. There are no lights on the dashboard, by the way, and the engine temperature is normal. It gets up to temperature nice and quickly but never goes over. Is this the filter cleaning itself?

 

Sunday (today), I still have no warning lights on the dashboard, but I've been out today for two 30-plus-mile journeys and cannot get above 22mpg at various speeds. I have noticed that apart from the first few minutes when you take your foot off the pedal, it stays in gear instead of going to "N" like it often does.

 

It still has that hot smell when you are near the front and a slight fuel smell. I noticed a few times today that it sounds a bit throatier than usual. Driving-wise, there is still no difference from normal. Is this doing a clean, or is it something else?

 

This is the first time in 10000 miles it has behaved like this. Thanks for any thoughts.

My understanding is that PPF regeneration differs considerably from DPF - the PPF regeneration is carried out during closed throttle overrun - so, unlike a diesel, it is unlikely for the engine to smell unusually hot after a regen.