Hi I'm having problems with my 2003 tdci focus on start up its sounds like its misfiring and smoking alot it's warms up and smoke goes but it still judders at low revs intill I floor it I had a snap on diagnostics on it comes up with maf sensor so I changed it and still doing it and still coming up with maf sensor would the map sensor cause it ? And the turbo at idle spools up up abit any ideas ?

Hi mitsimat


After you changed the senser did you reset the ecu by disconnecting the battery


If you didnt try that.

Leave it disconected for at least 30 minutes to allow the ecu to clear itself.


The ecu stores driving habits/fueling levels/errors/calibrations


Jamie

Ok I have put a new map sensor and a new maf sensor it still judders and losing power and really smokes in the morning it's been on a snap on diagnostics the codes are clear then I starts to run sweet as a nut then starts juddering and getting smoky as its doing it could it be injectors help me at my ends wits with this car thanks

Hi Matt

try the electronic accelerrator pedal, this is a common thing to fail, can give the same symptoms, can cost bit around £80 to £100 +

it could also be a stuck or gummed up egr valve , these can be removed and cleaned so will not cost anything but for a can of carb cleaner.