My 86 iroc lg4 is stored alot.sits for months sometimes.I have a 2year old reman. stock q-jet.Recently I drove it and got a code 21 I think is a sticking or bad tps??Anyway the light came on then went off after about 3 minutes of driving warmed up and the car never ran bad while the light was on.If the tps sticks for a second does this trigger the light and if the tps is stuck or bad wouldnt the check engine light stay on and the car run rough?thanks