Hey, ive been having this problem with my 2003 Honda civic, it has 161k miles and everytime i go to start my car it hesitates but when it finally starts the temp reads at operating temperature the second the car starts and the rpms are already at 900 when they usually start at 1500 and go down, the rpms would float around but i cleaned my throttle body and iac. i have no idea whats wrong, was thinking the map sensor but im not sure, would appreciate the help. Thanks
Your 20-year-old temperature sensor may be bad, feeding false data to the temperature gauge and fuel injection system.