I have a ford focus titanium 1.8 tdci 58 plate and the engine malfunction warning message has displayed itself twice now. the car seems to go into limp mode but there are no warning lamps or codes. it only does it when the engine is warm and at speeds of 50-70mph. ive had it into the garage and plugged into the scanner but it is showing nothing...ive checked the messages on the car but still nothing. it has only done it since I had the tyres changed. if I stop the car, remove the key then restart it, it drives a bit sluggish but then seems to correct itself and drives fine... im really worried as its only done 40,000 miles but because it is used more so now as a town car im worried its the dpf filter ....
any help or advice would be greatly appreciated