e46 weird idle issue

Hey guys, I'm a proud owner of a high mileage e46 and ive noticed the car idles rough at a stop such as at the lights. It will miss and the rpm guage will move slightly up or down, this happens occasionally sometimes it will idle perfectly fine. I've noticed it happens most when the engine is warm it seems to be ok on cold starts. I got the car scanned and a few codes popped up one for the o2 sensor and missfire in 3 cylinders (aware of this and will replace it soon) and another for the exhaust camshaft sensor. (Spark plugs and cylinder coils are new) I cleared the codes and took the car for a drive around the block for about 5 minutes. Scanned it again and the exhaust camshaft sensor came back up. Would this be the reason i am getting cylinder missfire or would it be something else? I don't want to spend money and still have the problem persist. No check engine lights or Service engine soon lights have ever popped up on the dash.



any help would be appreciated