So I have a code 12 that pops on after the engine gets warm more or less. maybe its the revs that trigger it, idk. but the light is off at starts and then turns off after a few minutes of driving around. I took off the egr and cleaned it out with brake clean. I lubed up the plunger a bit and it moves good. I took off the solenoid and tested its actuator, and blew into the hoses and such. it holds vacuum just fine and actuates like it should. I also tested the sensor with my multimeter. The power wire reads 5 volts with ignition off then goes to 0 when the car is on. The signal wire also performs correctly, reading 1.2 with the car off, but moving up as I physically move the plunger, and back down to 1.2 right away. I have detected a small vacuum leak in one of the lines over by the solenoid, which I haven't gotten to replacing yet.
As far as symptoms, there are some weird idle things the car does, but generally doesn't really affect performance so far. so I feel like I've ruled out the egr sensor, the egr solenoid, the cvc valve, and the egr passages being clogged. So what else should I check? I will update when I replace the suspect vacuum line, but I'm not confident that will solve it as the leak seems pretty small. I can't even see it visually, just can tell bc it stops whistling when I pinch the line section.