Yesterday for the third time my car was running very poorly. The electronic throttle control light (yellow wrench) came on and the rpm kept rapidly dropping about 1000 rpm like it was going to die. The CEL came on, and I shut off the car at a stoplight and restarted it. The ETC light went off but the CEL is still on.



Every time this has happened has been in the morning after it snowed. Last time I only warmed it up for approx. one minute, but this time was at least ten. I don't remember the first time. The first time it happened was a few weeks ago and it continued to do it until I got to a gas station and filled it up with 93 octane, just to be safe. I was at about a quarter tank. Yesterday I was a little over half when it happened.



Has anybody had this problem? Or can anybody smarter than me tell me what to look for? I had an appointment to get it checked at the dealership the first time but the CEL was off by then. Thanks!

 

It couldn't hurt to still have it checked at the dealer, there may be some stored codes pointing towards the problem.

Out of curiosity, did you have a quarter tank or less each time along with the freezing weather? I'm not sure where the ETC light would fall into this, but your gas line may be partially freezing.

 

I make it a point to never drop below a quarter tank in the winter, but I was pretty close to a quarter the first time it happened.

 

You've got to get us the exact trouble codes being thrown. If you car is under warranty, take it to the dealer. Otherwise, you can go to like an AutoZone and they'll pull the codes for free.
Post up what codes you get; it's not necessarily 'throttle' related.

And BTW, do NOT use 93 octane with the stock tune; the tune is not set up to handle it, and you're just wasting money.

 

Its a big guessing game without the DTCs that were set.
With the DTC #s, diagnosis is childs play.

 

When you refer to the ETC I'm assuming that is the wrench light. In my experience the wrench resets a lot quicker than the CEL. You should be able to drive to a dealer to get the code read before it resets. There shouldn't be a charge if you are under warranty but you might have to wait while. You could also try a local garage but they'll probably charge for a 1/2 of labor.
You're going to need to get the codes so if that suggestion doesn't work for you consider investing in a code reader. You can then carry it around for when it happens again. You can buy an inexpensive one off ebay. Better yet use this as an excuse to buy a flash tuner like an SCT or Diablo unit so you can step up the performance!