If it sits over night it starts hard, meaning you have to feather the gas peddle to get it to run and it back fires slightly through the intake. Only has 80K miles on it and has had synthetic 5w40 changed every 6k since we owned it from 49k. Battery is brand new and charged. I had a camshaft sensor code so I changed it with a VDO brand. Still got the same code, so I switched the ex and intake sensors and still got same code. I have removed and tested the VANOS solenoids and they are good. Only thing I can come up with is worn seals on the camshaft behind the VANOS. After it warms up it seems to start and run just fine, but I do think I have a low idle, between 600/800. Any other ideas?