I just bought this Altima at auction (cheap) and I am experiencing a sort of high RPM power loss. While in gear and under full throttle I cannot get over 4500-5000 rpm. It feels like I was hitting the rev limiter. I do not have any codes popping up or no CEL. In neutral it will get upto rev limit 6800RPM.
I did a spark plug replacement (PITA to do the rear bank) and it did not fix the issue even though the plugs were pretty worn and a bit over gapped.
I did notice while doing the spark plugs, that under the intake manifold the front cylinder intake ports have oily residue (light coverage not sludge) on them and the rear cylinder ports are nice and clean. I am sure that has something to do with it.
Also under full throttle there is a very throaty sound to engine, like if it had a cold air intake kit. But it is all stock.
Maybe a bad front Cat or injectors maybe fuel pump or filter??? any advise.
Please help!!!
Intake manifold removed
Rear Intake ports
Front Intake ports