I posted in All motor as well since i have AFR reading and a SAFC both which are on stock settings

At WOT or Part throttle over 60% above 4000 RPMS i have a sharp spike in my afr (14.9-15.1 WOT) and a loss of power and a nice rattle that goes along with it and it disappears around 5k rpm

I added 10% fuel to this range and it worked fine for a week or so and it came back today even with correction in the +

at idle i have an occasional misfire but i think it is due to a bad injector, fuel filter is a z32TT Filter and is 2 years old. I am almost wondering if it is my fuel pump that would be causing a surge.

Any ideas or anyone experience this in the past?

 

also MAF is original may be a possibility
no other symptoms than occasional misfire at idle and AFR spike WOT

 

Take a look at your exhaust flanges. Make sure they're all tightened down.

 

that was my first thoughts but it was intermittently, keep in mind im an ASE tech and i had my boss come over who is a senior master tech at Gettel nissan in Sarasota and we were stumped

I had a bad right side motor mount and i changed that thinking the bad mount would be tugging on the wires for the harness since i had seen that happen, i am not throwing codes at all.

I was told by my boss to check my cam sensor and i noticed a sludge build up on the gold part (assuming the magnet) of the sensor and i cleaned that.

I took it for a hard 15 minutes drive barely dipping below 2000 except stopping and a dozen 2 gear pulls 40-75 on the interstate and was unable to re-create the issue... so a possible issue fixed