It's not because she's a Shar Pei. It's because she's gotten into bad habits.
Time to re-educate her. Do you walk her daily? Is she getting all the exercise she needs? If not, that'll just aggravate the situation.
And if you're tense taking her out because you're expecting her to misbehave, she'll pick up on the tension and... misbehave.
Finally, ensure you leave the house before she does. Do not allow her to run ahead of you. That shows her you're the boss of where SHE goes, not the other way around. Every time she gets ahead, you stop her, sit her down, wait for her to calm down, then carry on.