car : 97 Legacy GT 5 speed. EJ25D This is kind of weird.... Today has been the coldest day this year. It was just below freezing outside. Until today it hasn't dropped below 45 degrees or so (or at least while I have been driving the car). I was on my way to work and stopped at the gas station. I left my car running outside to keep it warm. When I came back out, the idle seemed a little weird, so I gave it a small rev (to about 3,000rpm or so). When it dropped back down to its idle, it died. I started it back up immediately to find the Check Engine light was now on. I drove the rest of the way to work without any other issues. When I walked into the shop at work, I grabbed my code reader to pull the codes. It shot back P1507. idle control system [rpms higher than expected] On my way home from work (it was now about 50 - 55 degrees outside), I stopped at a railroad track. I shut off my car since it was a long train. When I started it back up, the light was then shut off. I did a total of about 15 miles of driving between the time the light turned on and then shut off. Is this something that I should be worried about? I do have a cone filter on my intake. Could I be pulling in too much denser cold air and throwing the code?....then just to have it go away when the less dense hot air is sucked into the intake later in the day? The one thing that confuses me is this code isn't set until you've completed two drive cycles with the malfunction.....
once again, when it gets cold all the gunk in your intake tract and throttle body hardens and things don't work. clean and clear
best thing to do is pull the TB off and clean it real good. then check your electrical. being 13 years old I bet a lot of crap has built up
I'll explain a little further. I removed the throttle body and cleaned the hell out of it, ran an FI service with seafoam, plugs, wires, fuel filter, etc I'll start checking over electrical stuff as best as I can tomorrow. Electrical is my downfall. Where would be the best place to start?