good day guys. Have a little question, started the other day, I am getting a code 61 on my display saying check gas cap. It is there and tight, So what can the problem be. there was some rust around the fill tube I cleaned it up and it still comes on. The SES light has been on for some time just don't have a reader. Also I little other question, what is the best plug to install in this car. (2000 SSEI)
I had the same gas cap problem. Check to see if the plastic gasket on the cap is OK. If so, clean the filler tube top seat VERY WELL and then clean the plastic gasket on the cap VERY WELL. Spray it with brake clean or some WD 40 and wipe it with Q-tips. There will be grit on it that is breaking the seal and setting off the code. You need to flush the grit off.
Now...put a little grease on the cleaned plastic gasket with your Q-tips and put the cap back on and off several times and then really screw it around and around a few times letting the ratchet click. Give the system a few hundred miles to clear the code. This worked for me.