Camshaft Position Sensor Help

First time post..... I have a 2008 Tiburon, 2.7 V6. For about a year, the check engine light would come on, it would read P0340, Camshaft Position Sensor. I would clear the code and it maybe came on a few times since then. No symptoms, just the check engine light.
Last week, the symptoms started suddenly. Stalling, can't accelerate more than probably 1/4 pedal, feels like it's not running on all cylinders, just generally running like crap.
I bought and installed a parts store sensor. It was fine for a couple hours, then back to problems. I then bought and installed an OEM Hyundai sensor, 39350-37100. It ran fine, till the next day, and back to the problems. I had disconnected the battery when swapping the sensors, so the computer would maybe reset.
Today I checked the wiring; nothing seems loose, melted, corroded, etc. I checked from the plug to where it joins all the other wires.
I want to avoid bringing it somewhere, cause you never know who's going to rip you off, or who is actually knowledgeable.
Sorry for the long post, but this is stressing me out. Thank you in advance for any suggestions.