HELP!!!! Misfire!! HELP!!!
03-12-2010, 07:05 PM
#1
HELP!!!! Misfire!! HELP!!! My car has been running good since i bought it and right now(10mins ago) It started vibrating and my SES light started flashing! I have never seen it flash before. I read the code with my obd2 code reader and its saying P0300 Random Misfire Detected. What the **** does this mean? i am ****** pissed as the car has been running perfectly...The plugs are new and so are the dam msd wires. Could it be a sensor that went out? Car has headers EGR and AIR was removed and the o2 sensors in the back were replaced by o2 simulators. The front sensors are plugged in to the headers...Please help me...
03-12-2010, 07:39 PM
#2
Just went to autozone and they told me it could be my crankshaft positioning sensor and the funny thing is on the drive to autozone the car started running fine and as soon as i came home put in park the car started vibrating alot and my obd2 reader picked up a
P0307 Cylinder 7 Misfire Detected. What do you guys think it is?? please help me as this is my daily driver car!
P0307 Cylinder 7 Misfire Detected. What do you guys think it is?? please help me as this is my daily driver car!
03-12-2010, 07:56 PM
#3
misfire hi, could be the plug or plug wire and possibly the coil. check the plug and plug wire and if that don't fix it switch the coil to another cylinder and run it and see if the random misfire moves to that cylinder. if it does bad coil. start with the plug and wires first. i had a bad plug after my header install and it did the same thing.
03-12-2010, 08:03 PM
#4
hi, could be the plug or plug wire and possibly the coil. check the plug and plug wire and if that don't fix it switch the coil to another cylinder and run it and see if the random misfire moves to that cylinder. if it does bad coil. start with the plug and wires first. i had a bad plug after my header install and it did the same thing.
03-12-2010, 08:50 PM
#5
I cant recall the firing order, but if your wondering which coil is #7 it's the last one on the drivers side. 1,3,5,7 driver's side and 2,4,6,8 on passenger side. And to add a comment, it's prolly gonna be your coils. I have a 98 with a 109k and had to replace all of mine last year. Number 7 went first then #2, then it seemed one every week. Theyre like headlights. When one fails the others arent far behind. I think they were $102 a pair at O'Reilly's. After my second pair they started giving me a discount on them lol.
03-12-2010, 08:58 PM
#7
I cant recall the firing order, but if your wondering which coil is #7 it's the last one on the drivers side. 1,3,5,7 driver's side and 2,4,6,8 on passenger side. And to add a comment, it's prolly gonna be your coils. I have a 98 with a 109k and had to replace all of mine last year. Number 7 went first then #2, then it seemed one every week. Theyre like headlights. When one fails the others arent far behind. I think they were $102 a pair at O'Reilly's. After my second pair they started giving me a discount on them lol.
...and thats exactly what the old guy at autozone said he told me to replace all of them because once one goes out there isnt very long until the rest join it. And its funny because i had a guy do my plugs and wires last year because i didnt have time to and i got thos MSD wires that have the little tags on them with the cylinder number and he put 2,4,6,8 on the drivers side and 1,3,5,7 on passenger side. Im sure you probobly know more than the guy that did mine so im taking your word lol...Thanks man. Trending Topics
03-15-2010, 09:32 PM
#11
Well my car started running normal again...it was still misfiring today so i went to autozone to see if they had the #7 coil. They didnt so i decided to go to advance auto parts on my way there i stopped at the gas station to refill since i was low on fuel. Filled up and drove to advance. Car was still misfiring at this point. I got to AAP's and shut off the car and went inside to see if they had coils in stock. They didnt so i said thanks and left got into my car started it up and what happens??...My car was running normal no more misfire it was idling smooth like it used to no vibrating. So i pulled out my OBDII reader and did a scan...and i got the same code as before which is the EGR message because i removed it when i stalled my headers. No more misfire codes and car ran good all day today. Very weird.....
03-15-2010, 11:04 PM
#13
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If you just changed your wires that exact same thing happend to me turn off all the lights in the garage and see if you see an arch trust me you most likely will if it comes back. When i changed the plugs i drove out from cali and everything worked fine i went through really thick fog and light started to flash and as soon as a came out of it everything was fine two days later came on again and looked under the hood and saw it arching off of the headers on the passanger side. I would try that before you change the opti its not likely that the opti got wet but the moister in the air and an exposed wire will make it do that but yes be careful when driving in the rain because of the opti.
Last edited by Drew24; 03-15-2010 at 11:12 PM.
03-16-2010, 11:14 PM
#14
Sorry if this question is retartded but what the hell is an Opti? Is it something to do with my EGR removal.?? I know the guy that helped me left a few wires just hangin around in the engine bay but nothing really hangs low to the ground except my O2 extension.
03-17-2010, 01:29 AM
#18
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Optis's were on LT1's NOT LS1's so with a 2000 you don't have one. Also PO300 can also be caused by vacuum leak.Here is a very informitive link about ruff running,check it out:
http://www.aa1car.com/random-misfire/
http://www.aa1car.com/random-misfire/
03-17-2010, 10:55 AM
#19
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