mis-fire on multiple cylinders and TCS light
 

I've got a 99 Honda Odyssey. All of a sudden the engine light came on
and the TCS light came on. As well the engine starting running rough.
The dealer ran the codes and said that their were mis-fires on cylinder
1, 2, 6, 5. The fuel pressure read ok (36psi). Plus the TCS codes
resulted from low voltage according to the tech. According to him low
voltage also caused the following codes: engine retard command (PFINH
signal failure), throttle position ref voltage failure, gear position
signal failure.

The battery test did fail, but it obviously has enough cranking amps to
start the car.

This dealer recommended that I replace all of the fuel injectors and
then fix the voltage issue later. I don't understand how I could go
from no problems to 4 cylinders mis-firing.
Any suggestions???