i returned my car back to stock. all my stock parts went in, still need to remove my 255lph fuel pump.
on cylinder 2 and 4, the injectors that i took out, the small shield on the bottom had broke off in my hand.
this is how its supposed to look.

and this is how two of them look (injector on the left)

they are not leaking fuel (amazingly?)

at first i was getting a po1399- manufacture control ignition system or miss fire
the miss fire was only below 5-5.5k rpm.

so then i changed the spark plugs, and o2 sensor, all was good until just recently these codes came up.
po300-random/multiple cylinder miss fires.
po301-cylinder 1 miss fire
po302-cylinder 2 miss fire
po304-cylinder 4 miss fire
po1399-manufacture control ignition system or miss fire

i didnt touch anything dealing with ignition (except for removing the coils)
now im either thinking its the injectors or the coils? im gonna swap the coils out tomorrow from my cl-s and see if that help or not.

 

My guess is the injectors.

 

also, it only starts miss firing after about 10-15min of driving. if i turn the car off and let it sit for about 15min or so, it will start to miss fire after about 5min of driving

 

i agree.. most likely its the injectors...

 

swap the coils and rememeber which one is which. if it misfires in different cylinders then theres your problem

 

Only problem is with these cars they often dont show the cyl misfiring. It usually shows a multiple 1399 with cyls that arent bad

 

i only had the cylinder 1,2,4 misfire code come up once. all the other times it would say missfire and never gave me which cylinder. so later on today im gonna swap out all the coils for good ones and see if that helps. if it doesnt help then ill get the two new injectors

 

well i took the car out today to go for a "test beat".
runs great when first started. after about 10min it starts misfiring but only between 1100-3800rpm now. WTF is going on.
about about 10min of stop and go traffic and cruising at around 5500rpm the misfire went away.
it peels out good, just like it always did. great pick up in 1st and 2nd (3rd is blown)
feels strong in all rpms now. and i can chirp 2nd gear.

i didnt change anything. still the same coils, injectors, and spark plugs (the ones i recently replaced).
im guessing it was bad gas bc the gas in the tank was from nov. when i started tearing my engine apart. im gonna take it out tomorrow and see what it does

 

It may be gas. Im still leaning towards an injector ???