so i went to the ref the other day to get my JDM Gs-R "re"bar'd and it failed cause my Hc's were a few numbers past the max output...nothing too big...maybe like 30 over the max allowed. everything else passed besides that. the ref told me my timing was too retarded...it was at 12 or 13 and it should be 15 or 16. my buddy keeps telling me its my cat but my cat only is only like 2k miles old. so i dont think it could be that. my O2 sensor is fine its semi new. so other then that im hearing people telling me to do plug, wires, cap and rotor...so idk, what do you guys think it maybe? i dont want to spend hundreds of dollars on something that seems so stupid and simple to fix.