98 Accord misfires when floored

I have a 98 Accord LX with the 2.3L engine and an automatic transmission.
Before I get into the details of the misfires let me give you some possibly relevant backstories. About a month ago the CEL came on with the code P1491 (EGR valve insufficient lift) but after about a week the light went out on its own. Then about 2 weeks ago i filled up the car on my way home from work and it was running fine. I didn't drive the car for a few days, but the next time I drove it it felt like the engine cut out for half a second and it would do that about once per trip which is about 12 miles. After about 2 days of that I thought it probably has bad gas so I topped it off with 2 gallons of premium and it helped a little. Then I got it down to about a third of a tank of gas and topped it off with premium. After that it was running perfectly... for about a week. then when I was coming back home from work the car didnt want to get up to 60mph so I kept pushing the gas pedal further and further until it was floored, but still not accelerating. Then the CEL started flashing (it was off prior to this) so I shut it off and pulled over off the road. I used my phone to pull the codes and this is what it said:

Current Fault: P1491-Powertrain: EGR Valve insufficient lift - from CEL in backstory
Current Fault: P0301-Powertrain: Cylinder 1 misfire detected
Current Fault: P0302-Powertrain: Cylinder 2 misfire detected
Current Fault: P0304-Powertrain: Cylinder 4 misfire detected
Current Fault: P0300-Powertrain: Random/Multiple Cylinder Misfire Detected

Then today I went to pass someone and it got up to about 64mph (According to the speedo) usually it shifts at that point but it just hung there for about a second then the CEL started flashing again. My phone didn't show any new codes because I never cleared them the last time so it just showed the same thing as above. When I got home I used my phone to clear the codes then on my way to work I ran it hard to see if I could make it happen again and after about the third time having it floored it didn't want to shift and the CEL started flashing. Below is the codes and the freeze frame data from when it happened

codes:
Current Fault: P0301-Powertrain: Cylinder 1 misfire detected
Pending Fault: P1399-Powertrain: Cylinder 1 misfire

Freeze Frame:
Fuel Status: 0 byte
Engine Load: 96.86%
Coolant temp: 197.6F
Fuel Trim Bank 1 short term: 0%
FTB 1 Long term: -1.56%
Intake Manifold Pressure: 14.21 psi
Engine RPM: 5,357 rpm
Speed (OBD): 56.54 mph
Intake Air temperature: 75.2F
Throttle Position (Manifold): 89.8%

Other Possibly relevant information:
The car has 244700ish miles on it
The distributor was replaced within the last year
The Transmission fluid was replaced a few months ago with the genuine Honda stuff the manual calls for
Has a new air filter
Spark plugs and wires should be in good shape (checked them around the time it was having EGR problems)
Compression is around 165 psi in all cylinders (tested at the same time I checked the spark plugs)
The car is green

Swap the spark plugs from #1 and #3, then clear codes & check results.

I need to think about this one.

Ok I will post back with the results. Also one idea I had was to take the parts from the old distributor and put them in the new one. The housing on the old one leaks oil, but other than that its fine. And that should tell me if it's the distributor or not.

It would, but I like to have answers first.

I swapped the plugs from cylinders 1 and 3 and drove it 12 miles trying to get it to misfire again, but it wouldn't. Also It took very little force to break the plugs loose. Maybe the plugs had worked their way loose somehow and that was causing all this? Also the plugs were golden brown like a perfectly roasted marshmallow

I think the problem has been fixed, but I can't call it just yet. I went ahead and replaced the parts inside the distributor with the originals (except for the rotor button and cap) because the car never seemed to have as much power with the new one compared to the original. I drove it 24 miles after swapping plugs then another 20 after swapping the parts in the dizzy and it's running pretty well so far.

It's not fixed. On my way home from work it did it again, but this time just cylinder 4 misfired.

xci and I dealt with this same exact issue with someone else earlier this year.

http://www.6thgenaccord.com/forums/showthread.php?t=50434

I'll give you the short version of it.

His compression was good.
He renewed his distributor.
Fuel seemingly was fine.
There is one similar code to yours that means random misfire, P1381. Therre is a diode that goes bad in the alternator that causes this one. His was fine. This can be tested for by pulling the green connector on the side of the alternator to see if the issue goes away.
I know you said they look fine but he said his look fine too. It wound up being his park plug wires. Now, the thing with spark plug wires is they don't always look bad in my experience. Here's the thing, there is only a few things in these cars that can cause these issues.

Bad spark plug
Bad injector

Right off the bat, these two are out because the misfire is switching around

Bad spark Plug wires
Bad cap and rotor
That alternator failure previously mentioned.
Bad distributor but the car wouldn't run if this was bad.

Before I try disconnecting the green connector on the alternator I would like to know what it does. Unlike the guy in the other thread my car idles fine. It only messes up when I'm really getting on it and even then it doesn't always do it. The last thing I want is to get stranded because I unplugged part of the alternator. Also the spark plug wires were replaced about 3 years ago and they all pass a visual inspection. Also I'm going to school for electronics engineering and I know how to test a diode. Is there any way I can get to it so I can test it with a multimeter?

Jpocolypse said:

Before I try disconnecting the green connector on the alternator I would like to know what it does. Unlike the guy in the other thread my car idles fine. It only messes up when I'm really getting on it and even then it doesn't always do it. The last thing I want is to get stranded because I unplugged part of the alternator. Also the spark plug wires were replaced about 3 years ago and they all pass a visual inspection. Also I'm going to school for electronics engineering and I know how to test a diode. Is there any way I can get to it so I can test it with a multimeter?

Click to expand...

The green connector interacts with the charge light and the ELD. I don't know of a way to test the diode as I have never tried pulling the alternator apart. All I know is it is there. But I don't think this is your problem. What brand are your wires?