for the last couple months my car has ran like shit! erratic idle, stalling, backfire, bad gas mileage, and sometimes would throw a code 45 CEL(running to rich or lean, wtf?) and sometimes would run ok. couldnt figure out what was causing it. so this past weekend i was cleaning the y8 head and i.m. i'm gona swap on soon, and i was using some STP intake and throttle body cleaner on it, so i used it on my y7 too, not expecting anything to happen, but to my amazement my car has been running great!!! no CEL, no stalling, nothing. smooth acceleration and idle. i guess i had some build up in the throttle body and the flapper was not closing all the way(which makes sense now). just wanted to share, might help someday.