Frigidaire FEF366DC Electric Kitchen Range "oven takes twice cook food" Questions

...takes and it was still doughy in sections with no rhyme or reason. the other night we had tried to cook the frozen fries and it cooked for three times as long and still was not cooked thoroughly. ...

...takes a long time to cook. There have not been any error codes. This problem began after cleaning the oven. Well my friend these type ovens have eyes and sensers. It could be that you left something ...