Hi
I have good water pressure everywhere in the house for hot water. However, in my shower head I loose the pressure and currently it only has 80% of pressure.

1)I changed the diverter in the tub spout and checked the single faucet catridge valve (which looks good since I replaced it 7 months back).
2)The shower head in the high temp setting gives > 2.5 gallons per minute.

This loss of pressure is after a earthquake which caused some leak on the cold water line in the water heater which has been corrected.