I have an F22B1 automatic and the transmission is starting to fail. Is the manual swap worth it or should I just throw a new automatic in.

 

How many miles, and how is it failing?
If it acts like it is in Neutral with whinning coming from the bellhousing, it is most likely the sump pickup is impacted with debris from lack of fluid changes. Fairly common issue on higher mileage H4As.
https://honda-tech.com/forums/honda-.../#post50667457

Tyler did an awesome writeup on where the sump is located, be careful in drilling the whole and the depth, clean it with brake cleaner and the trans will work again.

 

My Accord has 260,000 miles and the motor runs great. The transmission whines and lags between gears and has acted like it was in neutral when given too much gas. There is only one code [Input Speed Sensor] which I replaced already and the code went away and came back.

 

Always verify that the fluid is full.
I live in a hilly area and like to keep the AT fluid at the top of the hash mark of the dipstick with the engine running. Using Honda's method on a few off camber turns around here the trans will drop out at speed. But I drive like an ***, your results may vary.
With older transmissions, they will leak down a bit quicker. If you do check fluid the Honda way, turn the engine on, shift through every gear and hold for a moment, place back into Park and key off. Pull dipstick, wipe, reinsert(fully) pull out and check fluid level.
If the fluid was not regularly changed, ~250Kmiles is usually when these transmissions neutral out.
Whining is from the AT pump cavitation.
This occurs as the sump pickup becomes impacted with friction material, and why it is so critical to regularly change the fluid. There is no pan so only draining and refilling will keep the junk from building up.
What usually occurs is the trans will neutral out. Pull over/shut off engine let the car sit for 30 mins and the trans will work again. This is due to the clutch material falling out of the sump pickup, but it only falls down, so as soon as the engine starts the AT pump will begin to pull that material back into the pickup, blocking flow, no go, trans whines and it neutrals out.
Tyler was kind enough to measure where the sump is located in relation to the case.
Drill a hole, just deep enough to get through the case.
Blast the screen clear of debris, install a plug, refill, and the trans is usually functional again.

It gets worse when you apply more throttle as the load incrases needs more pressure to hold the clutches and the rpm increase creates more pump flow. Both contribute to the slippage.

Depends on what code.
Usually 9 or 15 occur from buildup on the magnetic pickups. They are hall effect sensors, if they are covered in ferrous material the signal resolution is lost and the TCM cannot command a proper shift point. You will either get a lazy or erratic up shift. Usually pulling them out and wiping them down(even when a code is not present) will improve shift characteristics.
VSS controls downshift points.

 

What about checking the fluid level with the motor running? This is the way I checked it on my Jeep Cherokee and other cars. I have a Hayden cooler on my trans and it is mounted fairly high, so run-back when the motor is not running could be an issue.