Well, I finally pulled the codes of my truck. 1990 2.3l 5sp. I had never done this before so when I pulled the codes i got 21, for engine coolant sensor, which i expected and then I got 33, for egr, but i got the same code twice. I did it several times and got the code twice. It was key on engine off. Why did i get the same codes twice? Also, I forgot to disconnect the jumper wire and was driving around with it plugged in and my truck ran much better at idle and during acceleration. I was going to leave it like that but I hoped someone here would know why it did that. As of now its disconnected. Thanks, Jason
