last year my 2005 toyota avalon check engine light came on.code#p0303.plugs and on 2005 Toyota Avalon

#3 coil was replaced.After repairs car ran very good,after about 10k the same thing happened check engine light came on code#p0303.The same repairs were made #3 coil and plugs.Again after a few week the light is on Code p0303.What is realy going on wiht this car anyone know ?Please anyone experience this let me know thanks.

2 answers
Suspect moisture contamination on # 3 cylinder in the spark plug well. Should be obvious when coil and plug boot are removed!
If this is the case find source of moisture. This is a firewall facing cylinder, poss rain or leaking coolant hose.
Was it a Toyota coil or an after market coil? The after market coil will not last.