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Q: just failed Mass Emissions Inspection. OBD codes P0303 and P0457. on 2004 Subaru Forester

What do these codes mean and are they expensive to fix?
Car runs fine and I am used to the CEL on (especially when it's wet out)But it had always gone off before this year. 130k miles.
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p0303 cylinder 3 misfire p0457 evap. system leak detected. Usually not too expensive. Cylinder 3 probably has bad spark plug or ignition coil. Evap. system leak can be found by a shop running a 'smoke test' to locate the leak and then repaired.
Thanks so much! Could the p0457 be from the gas cap? If the p0303 is coil how much would that cost apprx?
Are these dealership services or local mechanic?
Local mechanic can perform these repairs. About $100 dollars for coil plus labor. Evap. system depends on what they discover the problem to be on 'smoke test'. It can be just the gas cap has a failed seal and replacing could take care of it.
Thank You again! I am really glad to hear it's not something big and expensive. So glad I found this site and your valuable knowledge and experience.
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