misfire codes, idle surge, 1 injector Not burning.

[DavidV]

For some odd reason, my car passed emissions last time with the egr valve blocked (The hole in the intake manifold was purposely blocked with quicksteel. ), but didn't pass this time and was getting the code for it. So I took off the intake manifold to drill it out. After installing everything back on, I am getting misfire codes: 1300, 1399, 0303, and 0304. I checked over everything multiple times and made sure everything was tight.

I took out the old spark plugs and noticed the spark plug for cylinder 4 was lighter than the rest. So i got new plugs, installed them and ran the car for a while. It ran with no misfire, but had the idle surge. I got home today and started the car up, the misfire was back and the idle surge was gone. I pulled the spark plugs again and the cylinder 4 spark plug was almost completely white. I switched around the injectors and still the same thing.

What could cause this spark plug to be almost completely white?

EDIT: car is a 1997 honda prelude base.

Cylinder 1 is on the right, cylinder 4 is on the left:

[Barefoot]

get a noid light tester and see if cyl 4 is firing. if it isnt u got a wiring issue u need to handle for driving it anymore. or maybe even a bad ecu.

[EmminoDaGreat]

You probably have the vac lines mixed up for egr valve, causing it to be functional at idle instead of when it is supposed to. Causing a misfire .