I have a 2014 Dodge Avenger SE 2.4L (4 Cyl) Engine. I did a tune up yesterday morning by myself for the first time. I used youtube to help me do it. I changed out 4 spark plugs. I made sure they were the right ones. I put in 4 new IRIDIUM XP ED3 spark plugs. The guy at autozone where I bought the spark plugs told me to put on anti-seize all the way around the threads of the plugs. I did that, I made sure all the threads where covered in that stuff all the way around on all 4 plugs. I made sure the plugs were tight and I hooked everything back up the way the video on youtube told me. I also changed out the air filter. At 32,500 miles it was time to replace both the plugs and filter. The car acted fine all day yesterday after I did the tune up and changed the air filter. However, this morning the car started jerking and then gave me a solid engine light (it never blinked). Then after awhile I got the blinking red lightening bolt icon with the traction control light. I'm not sure what I did wrong, but I even noticed some of the gears shifted a little hard (P and N mostly), and when I turn off the car it sounds like it turns off kind of hard too, and there is also this thing I hear that shuts off too that seems delayed after I turn off the car, like 3-5 seconds after (maybe the timing belt?) That delayed turn off sound has been going on for awhile now even before I did the tune up and changed the air filter. No one is open right now for me to take the car to so I can have the engine code pulled, being a third shift guy sucks under these circumstances. Any thoughts or suggestions?