Please help. Driving home last night limited performance appeared on dash. No sudden loss of power but 5 mins later power started to dissapear until eventually the car stopped & wouldn't start again. Got towed home & plugged in reader. Codes showing were p0100 & p2279. I have stripped cleaned & freed off egr valve, checked vacuum pipes & inter cooler pipes. Vehicle will now start but will only run for 10 seconds. Removed maf from air filter box & started & can see what looks like exhaust gases returning through the maf. Am now at a loss what to do next. Does any body have any ideas?