With the team you're looking at you, you don't have any major weaknesses, but these are it:
2 Bug
2 Electric
2 Ice
And these are your resistances:
2 Ice
2 Bug
1 Electric
As it is your team isn't doing too bad. Lucario is a big ice-type counter, so you're good on Ice for the most part. Bug is not a giant threat, but I fear for Scizor. Scizor can sweep through your entire team if set up correctly, considering you have no fire-types. Electric can really hurt your team, so it may be good to have a ground-type somewhere in there. You may want to consider replacing your Piplup with a ground-type Pokemon and then filling in your last slot with a fire-type. This would give you a well-rounded resistance to ice, electric, and bug, while also eliminating an electric/grass weakness and adding a counter. I may suggest a Rhyperior for the Rock/Ground type to replace Piplup, and a Fire-type such as Heatran or a bulky dragon dance Pokemon like Salamence.