So I've finally thrown codes, and pending are misfires random, 1, 3, and 4. Confirmed is p1174 long term fuel trim. I checked data and it's defaulting to lean from a rich condition. Per your reply I checked the front o2, which is there and working based on all evidence (scan data/graphs). I then removed itfrom the bung to see how that affected the misfiring, per the clogged cat suggestion, and it seemed to do nothing or slightly slightly alleviated the misfiring. I'm stumped. |