No power/Hesitation at higher rpm or load

[macius8]

The actuators should move when turned on I think. For the vacuum operated 96 and earlier, they are that way. Then above 3k RPM (give or take 200rpm) then change position. So they are generally easy to check if they are working or not.

Well if they move it looks like they are working properly then. Mine is a 98, so it's electronic.
Looked at the codes again, now both banks are showing lean. Maybe it's a fuel pump issue... not delivering enough fuel under higher load.

 

[unity]

Or pressure regulator. Luckily fuel pressure is easy to check on these.

 

[BvilleStew]

Had issues with my '98 last year. Power dropped of at 3,500 rpm. No codes.
Checked IMRC, fuel pressure, plugs, etc.
Replaced the mass air flow sensor.
BAM!
It was like driving a new car!