Code reflecting the intake manifold & need to know where to start.
I recently had an issue where I started my car and it was idling weird but drove fine until I reached my destination. Then it started to rattle and idle hard and popped a code for the manifold. P340. I am not sure where to start in terms of figuring out if its the intake valves, manifold or the spark plugs. Maybe its none of those things but if someone could point me in the direction of some reasonable troubleshooting I would greatly appreciate it.