Can any one help me plz? My truck has 118000 and its idols at exactly 700 when warm every time. But when I first started up it idles at around 1200 to 1300 RPM for around a minute or so slowly dropping down to 700 eventually. I believe 700 is too high because when I let off the gas coast for longer than it should therefore using more my brakes and when I'm in park and I shipped it to drive there's extra where on my transmission. The truck runs great idols perfectly but I get bad gas mileage and there's extra where on my truck. I've checked all the vacuum hoses the air intake has no leaks all the sensors work and all the other instruments as well. I'm thinking maybe the previous owner flash the PCM with a performance package but I'm not certain of this. Does anyone know of a fix for this I could really use your help thank you. Also the lean bank one and two codes light up.

 

I would start by cleaning your IAC.

 

Duh! Waited until the last moment to toss that out there, eh?

You have an intake tract vacuum leak. Check it more thoroughly, you missed it.