-deleted and re-posted in Tmax folder-
Since you have a TMax you need to ask your questions over here....A diagnostic check showed code P0151 which is a lean O2 rear sensor and it was a historic fault.
...Any reasons for what happened anyone? I am running a TMax, K&N topless and a Rhinehart 2-1. ...
From what I read in the post that the OP moved to the Thunder MAX section he already knew what caused the issue. He was asking about the resulting P0151 code that his Thunder MAX system set, not what spark plugs to use.nothing to do with the Thundermax, it is the use of the wrong spark plugs that has created this issue, as is evident by issue self correcting once correct plugs were reinstalled.