My check engine light came on this morning on my way to work. When i started her up this morning it was 27 degrees out and she was really idling rough. Let her warm up and as the truck was warming up i noticed the tachometer bouncing- the engine was idling up and down.

Now i have two ideas -

1. I've got a bad tank of gas, however I'm about 1/4 of the way through this tank.
2. I'm running a Fram washable air filter that I washed and dried this weekend.

The owners manual says to wait through 3 cold starts to see if the light goes away, I'm thinking about going and buying an OBD II scanner.

Truck has 37,000 miles on it and is a 4.6L 2006 Supercrew.

Any thoughts or ideas?

 

Some auto parts store will scan your OBDII for free. Autozone is one that I know of. This would give you a go start and it is free. Got to like that.

 

Once you have the trouble code, enter it into the Goggle search box; you'll get tons of links you can read through that will inform you as to what's wrong, possible fixes (parts).

 

Might be your fuel injectors. I had a similar problem and that was the problem, but i have a 5.4L.