I have a problem with my Fiesta. I was driving along the motorway, and came off to a roundabout. When I pulled away, the car really struggled and sounded really lumpy.

Sorry for the lack of technical knowledge but this is what the symptoms are:

Exhaust is blowing alot of air out of the end and making what id describe as a chugging sound.

Car is down on power, but still runs.

Engine is running really lumpy.

Car is idling slightly higher than usual. (100rpm)

This morning I have changed the plugs, leads and air filter on the advice of my friend, all to no avail.

The car is well looked after and all fluids are to the correct level.

I have been reading similar problems on the internet which mention lambada sensors, MAF sensors, ECU's. Can't work it out!

Any help would be greatly appreciated.

Thanks