Check injection

[Christinalouise]

I'm currently driving a megane 1.9 dci and the check injection fault and service lights seemed to come on and stay in for most of the time. I've had the injectors checked and they're fine there's no loss in power either. I've even had new glow plugs starter and a battery and a full service recently. Any suggestions on what it could be please? As it is very annoying. And also sometimes when I put my foot down a little quite a lot of black smoke comes from my exhaust. Any suggestions what it could be? Tia

[AlexB]

This literally means check the injection computer for stored fault codes. Injectors are only a part of the whole system.