Hi! I have a 2001 Kia Sportage 4 WD. It has been not accelerating well for a few months. Like when I turn it on sometimes it tries and then shuts off (like maybe once every other day or so) and when I start driving it takes FOREVER to get to even like 20 mph. The 1st time I drive it after a few hours it literally crawls for 2 minutes and then picks up slightly. Anytime I accelerate from a stopped or a slowed position it takes ages to get up to speed. The car will eventually get to 3500 or 4000 RPMs then back down and be at a normal speet. I can feel it shake a little and hear a thunking noise when I accelerate. At first we thought it was because there was a hole in the muffler so we had that replaced. No improvement. It is throwing crazy codes apparently and the guy at Meineke recommended that as a starting place but had no idea. The service engine light will blink then go solid. Its truly bizarre. Any ideas?