Help needed
 

We have a 2005 Mazda 2, that my wife uses as a daily runner, yesterday i had to tow her home as the car was making a put put noise, and there was greyish black smoke coming from the exhaust and the car had no power what so ever it is a 1.4 td, i think the put put noise is down to a blocked injector, i am just wondering if this would cause the smoke and the serious lack of power thanks in advance