Lady needs Help

Ok guys....I took my 1997 Mercury Sable to Midas to get a oil leak fixed they told me the oil was leaking from the vale cover & the oil pan so they had to replaced the gasket on both.

It looks like the oil is not leaking anymore but now my checking engine light is on and when I'm at a red light my car seems like it is jumping like it wants to take off or something this has never happen before only when I got my car back from Midas....I going to take my car back there but can somone tell me what can be causing this?

Thanks

Sounds as if they left a cable disconnected.