I've had my truck for about 3 years now, and bear with me I'm still learning a lot. There are a few problems I have been having. The first issue I've been having is my RPMs seem to be a lot lower than they should be and I've already bumped up the idle valve. It also occasionally drops so much it stalls as soon as I turn it on. The next problem I have is when I'm in 5th gear and stay at about 2k RPMs my check engine light always comes on, and that's the only time it comes on. I've been looking a lot of things up and I'm not sure if the problems are related but any tips or help would be great!

 

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