Hi all, first time poster, so please be gentle. I have a 2008 aspen with 225k miles on it, though the diff was replaced with a used one with approx. 70k. It drives fine ( aside form needing two pulleys replaced in the last 2 months, they both happened to fail while driving which was awesome),and crappy gas mileage ( 11 mpg city) but I inherited it with a check engine light on, and a bunch of codes. The codes are: p0455, p0456, p3425, p3441, p0882, p0876, and p0750. I know, its a lot. Now given that, my wife has been driving it on a daily basis, and hasnt had any noticeable issues, to include 100 mile round trips. I am a bit of a youtube repairman, mainly because labor charges kill me and I am hard headed enough to try to fix stuff on my own when I can, but these codes are things I have never dealt with on my other vehicles ( 99 suburban, and 04 grand marquis). Are these codes things that need to be taken care of pronto, and in a certain order, or are they not a huge deal, given that we dont seem to be experiencing any performance issues? Any insight would be appreciated. Thanks!