I have a 2005 KIA Sorento LX. when I start it, it shakes a little and barely fires and then stalls. Other times, when I put it in park it suddenly idles really high for a few seconds, other times it barely makes it to 1000 rpms when sitting at a stop sign and stays at 2000 rpms other times while sitting at a stop sign. It also has a slight vibration, not even a shake. it is so slight that it makes me nauseous.....? The check engine light didn't come on for awhile then it did. It stayed on for a couple days then went away but the problems still persisted.

SOURCE: remove factory radio

This is one that you can stare at all day. the trim pieces that include the air vents (usually woodgrain) will come off and expose the screws that hold the radio in. They are held in by spring clips, a gentle pry will get you started. Here is a website that shows how to remove one for a cell phone mount: http://www.bracketron.com/main/xmain_landing_page.php You may have to take the climate controll screws out to get the radio out far enough to reach the plugs on the back. You should be able to figure out the rest. good luck, and be gentle.. the trim is getting cheaper and cheaper, and is really easy to break.

SOURCE: 1992 Toyota Camry Rough Idle

start by pulling hose off egr valve see if idles smoother almost instantly

SOURCE: gas mileage

Whenever I use the heater, my gas mileage goes to sh*t . If you've been using the heater all the while, and suddenly this happens, you may have a clogged air filtre or not be firing on all cylinders and may require repair. Check your filtre first, but for cylinders, a good indication is your spark plugs - if they're wet, coated, or corroded, this may be part of the problem. KIA will charge you a lot to do this, and if everything is fine, you could be out almost $800. See my thread on spark plug replacement.

Another problem that may effect your consumption is your timing belt. Check how many miles or KMs you have and see how close to servicing you are. If you are within 3000mi or 5000KM of scheduled maintenance, get it done. It cost me $640cad. I would not suggest doing this yourself.

Best of luck.

SOURCE: The A/C my 2006 KIA SORENTO LX with 37,000 miles

Your A/C compressor clutch probably is shot, and the A/C system is not pressurizing and pumping refrigerant through the system. Take it to a shop.

SOURCE: Engine shakes when Idling/ Check Engine Light started blinking

i just fixed a similar problem on my van there is a rubber elbow on the end of the pvc hose that connects to the valve cover you can only buy the elbow with the hose and it costs about 100 bucks but i guess they have had to replace a lot of these because the new one looks twice has strong you just have to check and see if its collapsed in on itself preventing air movement or leaking the shop will charge you 175 dollars to fix it plus the part but it only takes 20 minutes good luck