Check engine light on after injector cleaner added to tank

[roz84]

My hubby put an injector cleaner in my car this morning, (I don't know which one but it wasn't redex) a couple of hours later the check engine light has come on! Could it be related? It's got its MOT tomorrow so it's a bit of a pain...

[stevieturbo]

Very unlikely.

But why did he do it in the first place ?