I have a 2003 325i SULEV throwing 28B6 (intake camshaft mechanical) and 28B8 (exhaust camshaft mechanical) codes which indicate a problem with the dual VANOS. Car is idling rough and I feel rumbling in the engine at high speeds. Took it to an indy shop...said VANOS needs to be replaced...did the job for $1600 (vanos, CPS, solenoids)...got the car back and codes came back after 100 miles. Bringing it back this Monday, but would like input from the community on other possible causes. Assuming they did the install correctly, could oil pressure be a factor since both cam codes are throwing...thanks in advance.