What is causing my misfiring?

[f$nsho]

For the last two weeks my engine has been intermittently misfiring. The SES light pops on, the engine starts to run really rough, the RPM will drop to 500 when idling and only run up to 1700 RPM at 70 MPH. It comes and goes just like flipping a switch.

The codes I am getting are;
KOEO: 216 (Primary circuit failure – ignition coil 2), 212 (Ignition Tach signal was erratic (module/ wiring) or Spout circuit fault).
KOER: 167, 225 and 116.

Any ideas what this may be?
I initially thought it was my fuel pump that finally gave way. It was always pretty noisy, but for a three day period it was just a really loud whine. Now I can still hear it prime before starting, but the excessive noise is pretty much gone. Do these pumps die so slow that they will cause the engine to run the way it does?
Also, I had water leaking into the passenger side floor compartment and am thinking this maybe has caused some damage to the ECU? Is there a way to check?

Checked the grounds and they seem fine.
Any ideas what this may be? Thanks in advance.

 

[925spdsho]

Im gonna say its the DIS module, I had a similar problem with my 92.

 

[bubba]

it could be plug's too? Wire's? Just throwing thing's out there

 

[firstgen89sho]

not with the 216 code, plug wires would not cause that

 

[itwonder]

CPS 1st suspect, DIS 2nd suspect

 

[f$nsho]

I finaly got to working on the car Saterday and switched out the TPS sensor on account of code 167-Insufficient throttle position change during dynamic response test. I have driven it a 30 miles since and it has not acted up yet so I am starting to think that may have fixed it. Got a way better responce to the gaspedal as well
During the two weeks I have been dirving arround like this I may have done some damage to the exhaust since I got a low rumble fromt the outtakes. Don't know what this is but will check this out next weekend.