Is it possible D dimer, CTPA, PET scan, ultrasound missed a PE? 2 years later I have the same SX once again- throbbing leg, cough, stabbing chest pain

No,they did not miss. No relation between what happened 2 years ago and now. You may be having a new episode of PE now and 2 years ago, you did not have it.
It's complicated. A person who has normal D-diner and normal CTPA does not have a pulmonary embolus (PE) AT THE TIME THE STUDIES ARE PERFORMED. Normal studies two years ago have no value in diagnosing current symptoms. An ultrasound exam of legs may diagnose DVT (deep vein thrombosis) but tell nothing about PE. A PET scan is worthless in diagnosing PE or DVT.