My ford focus sport 55 plate is jerky in second gear but fine 1 st and 3rd , has anyone have ideas on what's wrong with it . Thanks

Hi I'm wondering is this happening around the 2000rpm mark. I believe this can be down to O2 sensors or something. Basically same thing happened to mine after being de catted
An it was discovered that one of the O2 sensors was not registering so the fuel mixture or something was screwed up. Best bet try an get hold of a cheap diagnostic fault reader to see if any codes come up.