I have a 2005 PT Cruiser 2.4l (non-turbo) that has over 100,000 miles. The check engine light came on and the codes were 0303 and 0340. I have had new spark plugs, new coil, new camshaft position sensor and new fuel injector in #3 cylinder. The engine light is still on and still has code 0303. What else could be the problem?