2002 Accord F23A4 auto, low power on hills and fishbite roughness on flats.
No CEL.

187K miles, well maintained, one owner (me).

Last year it could climb a certain 8% hill in 3rd gear, 50mph.
This year, same hill shifts down to 2nd gear, 40 mph.

Also noticing fishbite roughness on flat roads at steady 40-50mph.
Cruises at 75mph well. Idles well.

Not sure if it's a motor issue or a tranny issue.

Here's what I've done:

compression test - 180/170/185/180
vacuum test - 20" steady at idle, does not drop at high rpm
exhaust backpressure test - 1.5psi at 2500 rpm

adjusted valves - they were about right

fuel pressure - 44psi at idle, 50psi at higher rpm
I did not check fuel pressure when driving up the hill.

Air filter is clean.

New NGK plugs and wires (they were due for replacement)
New Honda distributor cap and rotor (also due)

I checked the 2 dual trans solenoids.
Linear was clean and within spec for ohms.
Lockup screen was very dirty, I cleaned it out. Ohms in spec.
Did not check the lower 2 solenoids.

Changed the trans fluid with Idemitsu type H-plus, 3x drain and fill.
Old fluid was not bad, I've done 25K mile drain and fill for a long time.
A little material on the mag drain plug.
Today I added a tube of Lube Gard Transmission Lubricant Instant Shudder Fixx, did not seem to help.

I have not checked the egr valve/passages or the injectors.

Running out of ideas.
Comments are welcome.

 

when were the brakes last serviced?

I'm just thinking, vibration and low "power" could both be related to a seized caliper or stuck e-brake

 

I don't think brakes are the problem, the wheels never get too warm.