Injector 1 displayed

[Molej31]

Hi all first post be gentle!

Engine light is on so…. A mate of a mate of a mate! has plugged in his diagnostic scanner for my 2006 C200 Elegance and it has brought up:
Zero quantity calibration for the cylinder 1 fuel injector The maximum activation period is exceeded.
I do feel it has lost a little bit of power but nothing major, wondering, is this a big job? Replacing the injector (or do I have to have them all done) also will it damage the car if I carry on and ignore it?
Not sure if it might have been to do with me (in lockdown boredom) changing the flow plugs they did need doing mind you and the didn’t snap!
Thanks in advance.

 

[supernoodle]

Zero fuel correction is the long term injector drift compensation. You should be able to see the individual cylinder correction values (in microseconds) with the diag tool. I expect a set for low, mid and high rail pressure.
From the wording of that fault I expect it's having to adjust for an under delivering injector, but has reached the limit of how much it can compensate. Checking the data would confirm.

Note, the system can't really distinguish between an injector issue and a cylinder with low compression. It works by opening the injector in increasing amounts during an overrun until a response is seen on engine speed signal. As you did glow plugs, make sure that cylinder is ok first.

If you determine it is injector, you only need change the one.