Like what
@Roger rabbit said, too deep and too low. I hardly ever get pip in my quad or any other muscle no matter what the compound is. The only time I ever got pip in my quad was from injecting too low or too central above the femur, and instead of outer. You can also get pip in the quad from injecting too fast as well. There are more nerves in the quad, and when you push the oil too quick it sits heavy in one spot and pushes up on those nerves. I hope I explained that right...you guys know what I meant.
Edit: I have gotten pip from injecting into a site that had been recently injected into as well