As a quick back story, when driving home recently, I pushed my pedal to accelerate, the engine lurched, then engine speed dropped to idle and a drove home at about 1mph. I found that the endplate on the linkage rod coming from the firewall had come loose and wasnt moving with my pedal. I took it apart, matched up the rotation angle as best I could, and welded it. For 2 weeks now the car has been driving great, but today (very cold day), the throttle has been acting up in a strange way. When in park, if I rev the engine, RPMs drop back to idle quickly as they should when I let off the pedal. When driving, the RPMs return to idle slowly, almost as though the throttle linkage is sticky or poorly lubricated. But it doesnt behave this way when in park! Has anyone experienced this issue or have any thoughts on it?