Hello all. I have a 2011 Toyota Avalon limited. Been getting a code p0303 misfire. Had everything check and told all is working fine but check engine light still on. One mechanic said it was the computer needed to be replace. I just changed my battery and the light turned off for a few days, came back on last night. Spent thousands of dollars at dealer in Venice Fl. And didn’t get fixed. What could be the reason for the check engine light still being on.? Thank you.
P0303 is Cylinder #3 Misfire. Can you tell us specifically what was checked and claimed to be “OK”? If you move the spark plug/coil to a different cylinder, does the code move to that cylinder?
For further troubleshooting see our misfire sticky under FAQ:
https://carkiller.com/scottykilmer/qa/misfire-4/
Also, see here:
https://www.obd-codes.com/p0303
Additionally, stop going to that dealer- they clearly didn’t help you and took your money in the process. Troubleshoot some of it yourself, as well as take to an independent, honest mechanic from now on.
