Hello I have a 2005 Ford Fiesta St150 and I have bought some new fuel injectors and I replaced them with Bosch Blue updated injectors bought from Pumaspeed I gave it a drive after I fitted them but now my engine management light is on and when I was coming out of a 30 mph road onto a 60mph road I accelerated and I saw a thick film of exhaust fume's covered the road in smoke it wasen't blue it was just normal colour exhaust fumes then it cleared and and was fine but it has a slight misfire while driving but the car can be driven as the misfire isn't all the time starts up fine with no misfire when I looked at these injectors it said they were a direct fit but I plugged in a code reader and I have a P0200 Code which means there is an electrical fault in the injector circuit I don't want to fit the original injectors as these I bought were not cheap and the original injectors had over 90,000 miles on them what do I do can any body suggest a repair 

 

 

So you fitted richer injectors, you now have a misfire and the engine management light is on.

Constipated, Holmes?

Wouldn't have expected anything else really. Either put in standard ones or uprate the rest of the engine to match the injector. You won't be doing that without a visit to a rolling road anyway so go and see if there is one out there that can retune the car before you poison the cat and wreck the O2 Sensors.