Missfire at WOT. p0304
#1
08-18-2011, 11:53 PM
Missfire at WOT. p0304
I been trying to find the problem with my car missfiring issue.
the car does not missfire at idle or at normal driving condition.
whenever i gun it (wot) my car missfires code keeps showing up p0304 cyl. 4 missfire.
I changed the ignition coil and the sparkplugs at first. then it was okay for couple days and the car starts slight missfiring randomly even at idle, so i checked into it and found igntion coil harness cracking and cracked so i wired new igntion wire. After that was repair car was okay for more than about 1 month. After that car started missfiring at whenever i gun it(wot) car just missfires and when i check it its always p0304. I checked compression and it read 148psi @cyl 4 which is in spec. i starting going deep and started ohmming out igntion coil harness and didnt find anything wrong with it. It got me thinking can it be the ecm bad? or something else.
I also check throttle body and i found carbon and some engine oil sitting at the throttle body.
therefore i cleaned it up all good and cleaned out the intake pipes. while i was cleaning out the intake pipe the lower pipe by the lower intercooler, when i disconnected it engine oil started dripping out about 2 shot cups of oil. Therefore i thought my turbo is bad, so i checked the intake pipe at the turbo side and there is no signs of oil nor it was wet with oil. i found this strange, b/c i thought it would be wet allround. intake.
i dont know if my turbo is shot or not, when full boost tries to kick in engine starts missfiring and i heard like metal clanking sound just like the sound when cat is broken inside. Also i gutted out the cat. btw made it stright pipe b/c my cat was clogged b4. I dont know from my cat being clogged messed up the turbo or not.
my main question is can bad turbo trigger missfire p0304 only whenever i WOT? I dont know where to go bad ECM or Turbo? whenever car want to full boost engine missfires and triggers p0304. weird i dont get it. turbo seems like it wantting to fully boost and i hear turbo spooling, but it starts missfiring during boost and there is no white smoke(only at cold start but goes away after warm up.
any tips or hints guys? whats so special about p0304? is my knock sensors being stupid?
the car does not missfire at idle or at normal driving condition.
whenever i gun it (wot) my car missfires code keeps showing up p0304 cyl. 4 missfire.
I changed the ignition coil and the sparkplugs at first. then it was okay for couple days and the car starts slight missfiring randomly even at idle, so i checked into it and found igntion coil harness cracking and cracked so i wired new igntion wire. After that was repair car was okay for more than about 1 month. After that car started missfiring at whenever i gun it(wot) car just missfires and when i check it its always p0304. I checked compression and it read 148psi @cyl 4 which is in spec. i starting going deep and started ohmming out igntion coil harness and didnt find anything wrong with it. It got me thinking can it be the ecm bad? or something else.
I also check throttle body and i found carbon and some engine oil sitting at the throttle body.
therefore i cleaned it up all good and cleaned out the intake pipes. while i was cleaning out the intake pipe the lower pipe by the lower intercooler, when i disconnected it engine oil started dripping out about 2 shot cups of oil. Therefore i thought my turbo is bad, so i checked the intake pipe at the turbo side and there is no signs of oil nor it was wet with oil. i found this strange, b/c i thought it would be wet allround. intake.
i dont know if my turbo is shot or not, when full boost tries to kick in engine starts missfiring and i heard like metal clanking sound just like the sound when cat is broken inside. Also i gutted out the cat. btw made it stright pipe b/c my cat was clogged b4. I dont know from my cat being clogged messed up the turbo or not.
my main question is can bad turbo trigger missfire p0304 only whenever i WOT? I dont know where to go bad ECM or Turbo? whenever car want to full boost engine missfires and triggers p0304. weird i dont get it. turbo seems like it wantting to fully boost and i hear turbo spooling, but it starts missfiring during boost and there is no white smoke(only at cold start but goes away after warm up.
any tips or hints guys? whats so special about p0304? is my knock sensors being stupid?
Last edited by a4ak4boost; 08-19-2011 at 12:14 AM.
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