I checked my code reader today I do this every few months to see. And Taday I got a code 21 and code24. 21 is the collant temp sensor I have changed this 3 time in the last 2 and a half years don't know why last time with a ford one??? and I guess I need it again. But code 24 intake air temp sensor I don't think I have one on I my 1989 that was made in JAn of 89. I any one could help thanks It's a 1989 Mercury Grand Marquis Wagon 207000KM