Misfire nightmare

[groupbmonster]

So I'm trying to deal with a misfire on cylinder 2 that my 98 LGT has had for a while and was hoping you guys could lead me in the right direction.

Misfire on cylinder 2 and occasionally throws a catalyst insufficient code also.
Plugs were replaced with NGK
Wires were replaced with NGK
Coilpack has been replaced
Injectors have been checked and given the OK
Front 02 sensor is new, rear is 2 years old
Front and rear catalyst are about 2 years old

The car was just in the shop about a month ago because it would not idle and was missing on all cylinders, stalling and generally running like garbage. The maf was replaced and a bunch of stuff was checked out and all looked good.

Just got back from the smog shop and it passed the sniffer and the evap test but threw the CEL for misfire cyl2 while being tested... Just my luck.

The car runs fine otherwise, doesn't stumble and I'snt down on power as far as I can tell.

It is all stock except for a magnaflow muffler, I took my UEL header off a few months ago because of my pending smog test.

Any ideas about what else could be causing my problem?
I am officially stumped :smt017

[Dead91silvia]

Interesting... Many EJ25's I have seen toss a P0400 code for the EGR system, but this is not the case. You might want to see about at least cleaning that system though. Might be a good idea.

Also, maybe try a compression test on cyl 2 if you can. Might be a long shot, but it could be a head gasket. It would be an odd one, but its not much work to just check.

You have changed all the parts I would have... Might also be an ECU problem, but I dont think it would be...

[groupbmonster]

Oh yeah I forgot to say the shop and I both did compression tests, results were good. Not awesome but definitely not bad enough to cause a problem. No coolant in the oil and no oil in the coolant, headgaskets were new 2.5 years ago when I bought the car.

Egr system was looked over by the shop and was ok but it might need a deeper check.

I thought of checking the ECU, that is a very expensive maybe and doesn't seem to fit the bill but who knows.

Are there any other parts in the ignition system before the coil that could cause a misfire on a single cylinder? I didnt think there was but most of my experience is with distributor ignition systems so I may be missing something.

[d1giPhux]

I was getting misfires on all cylinders / random cylinders and it turned out to be the exhaust gasket(s) between the cat's starting to rust out. Definitely worth a check. If yours even LOOK rusted, chances are its causing the problem. Once i started to poke at mine, they literally crumbled apart and fell out. Replaced one, and the other blew out right after it. Definitely worth checking out.

[groupbmonster]

I will look into those since I have replacement gaskets already.

Turns out the shop only tested the injectors for duty cycle not spray pattern and flow so I am gonna get a different injector to drop in on that cylinder and see what happens.
Fingers crossed.

[groupbmonster]

So I was looking up info on injectors and have come across 2 different types of the same red injectors.
https://sl-i.net/FORUM/images/imported/2012/05/32oD3-1.jpg
https://sl-i.net/FORUM/images/imported/2012/05/xKkKD-1.jpg

Anybody know if there is a difference between the two other than visual? And what ones would be in a 98 LGT 5MT Sedan?