Thread: Code PO305 ... will not go away

My 98 GTP is ... well for a better word "Pissing" me off.
I have Code P0305 ... Cylinder 5 misfire detected ... Mod $10
The engine light is on and flashing, not solid.
I have changed Spark plug wires, Spark plug, 2/5 module, ICM, and even went into the headache of changing the fuel injector.
The car is running ... oh lets say 60-70%, I'd go as high as 80% of normal
The car is bogging down a bit, until I changed the fuel injector, is was idling really rough, not ... so so.
I need some help on this, this is the only code she's throwing, and I want to get rid of it, and have my baby back running smoothly

Chuck

@ Blueguy
No, no Mods
The plug that was pulled looked ok, little light brown on the end, and running 91 octane
I changed the crank position sensor, prior to that had cylinder 3 coming up, now that's gone, and replaced with cylinder 5 error code.
Do not know about the Cat ... it's been on since I have had the car, year and a half, rest of the exhaust system has been replaced though. Is there a way to check it?

Got someone coming over in an hr or so to check the Cat with a lazer heat reader... will know then if the Cat is the culprit! Even though I don't want to buy a new Cat, I'm hoping it's the cause.

Alright, now I'm at a loss..........
We took temp readings of the Cat ... pre Cat 215 degrees and after Cat 345 degrees.
Thats what it is suppose to be, no?
Cylinder 5 still not firing, I disconnected the injector wiring off it when it was running, made no difference, so that proves that the code is lugit

Guess I"m stuck with doing the cylinder compression test next

Ok, did compression check on the fnt 3 cylinders...

#1 - 85
#3 - 90 and
#5 - 60 Ibs

You think this is enough to make #5 not work, cause it is obviously not working, I pull the injector connection off of it, and have no difference in the way it runs, so something tells me that number five is ....DEAD

What should the readings be?
Could it be the lifters, or valve seats, or both?