1999 Mercury Marquis I got the code 181 fuel temperature SE

When I read the code 181 say range perfomance what I can be need to change sensor or something for the 442 I all ready change the gas cap the code come about every 160 miles after I fill the tank and I erase the code again the car just knine esitates between 45 and 53 miles a hours when you flooring it every thing is fine thank you for your help sincerely roland