Hello. I own a 2003 Mazda Protege ES and it has been running fine for the 8 weeks that I've owned it but it suddenly has begun giving me problems. The check engine light is on and blinking and it's throwing out three codes: p0171 (System too lean), p0301, p0303, and p0305 (all of which are cylinder misfires) and p0455 (System Gross Leak Evaporative Emission). Now I'm not what you would call savvy with car repair so I just want some opinions on what might be causing all of these codes. Is it one thing or a number of things that need fixing and what should be checking first. Any suggestions are good suggestions. Thanks!

 

I would start with the EVAP leak. You can find more details here.

https://www.obd-codes.com/p0455

Once you verify you have a good cap, reset the codes and try again.