2005 Dodge Neon Check Engine Light,

Ambient air senson circuit low and high (P0071 and P0072 respectively).

Also has P0300 indicating engine missfire.

I've ordered the ambient air sensor that mounts to the air cleaner (intake). Its only $12 so I thought I would start there.

Dealer suggested I next try the O2 upstream sensor next.

Any other suggestions? Any change its bad spark plugs or wires?

Gene