P0300 for the last 5-6 years.. shot in the dark
02-19-2020, 11:37 AM
#1
P0300 for the last 5-6 years.. shot in the dark
Hey, I haven't really posted a whole lot on here, in high school I was on 6thgenaccord all the time, it was my first car.
Anyway, I mean to preemptively apologize if this thread isn't in the correct place and if this has been solved, I've looked believe me.
Short summary, it's a 2003 CL-P years ago I had a coil pack die in a parking lot, I limped it home and by the next day got all of them replaced with OEM packs.
At some point near that time I've had an issue with WOT where the car (around 70mph @WOT) almost always loses power instantly and drops to 3000rpm bogging as if it's in limp mode.
Not shortly after noticing this I replaced all of the spark plugs, didn't seem to resolve the issue, every time this happens it throws P0300 random misfires w/ different cylinders.
I know this may sound like a terrible thing to do; but if I let off the throttle and coast, turn the key to the off position WHILE the car is rolling and bogging and then turn it back to on position the CEL stays but the car stops bogging at 3k rpm as if resetting the ECU directly afterwards takes it out of limp mode.
If I get back on it WOT it happens again 90% of the time.
I also had an issue the last couple years with the car not starting when hot or cold, randomly, etc which I eventually resolved after concluding it was the Main Relay (fuel pump not being powered on properly) which I thought potentially this was a long term side effect of that relay but the issue still exists and is still easily reproduced.
Every time I go to get emissions tests I just reset the battery in the parking lot to drop the codes and obviously don't WOT in their parking lot, pass and go on with my life.
If anyone has had some experience with WOT causing misfires and limp mode I'd appreciate the input,
Final thoughts and information, I have a 2.5" catback to 2" Y pipe, I have also considered it may be a cracked O2 sensor if they are on the bottom of the J-pipe somewhere as I also have suspension.. but to be quite honest I've never really remembered to look at it over the years.
Thanks for any input!
Anyway, I mean to preemptively apologize if this thread isn't in the correct place and if this has been solved, I've looked believe me.
Short summary, it's a 2003 CL-P years ago I had a coil pack die in a parking lot, I limped it home and by the next day got all of them replaced with OEM packs.
At some point near that time I've had an issue with WOT where the car (around 70mph @WOT) almost always loses power instantly and drops to 3000rpm bogging as if it's in limp mode.
Not shortly after noticing this I replaced all of the spark plugs, didn't seem to resolve the issue, every time this happens it throws P0300 random misfires w/ different cylinders.
I know this may sound like a terrible thing to do; but if I let off the throttle and coast, turn the key to the off position WHILE the car is rolling and bogging and then turn it back to on position the CEL stays but the car stops bogging at 3k rpm as if resetting the ECU directly afterwards takes it out of limp mode.
If I get back on it WOT it happens again 90% of the time.
I also had an issue the last couple years with the car not starting when hot or cold, randomly, etc which I eventually resolved after concluding it was the Main Relay (fuel pump not being powered on properly) which I thought potentially this was a long term side effect of that relay but the issue still exists and is still easily reproduced.
Every time I go to get emissions tests I just reset the battery in the parking lot to drop the codes and obviously don't WOT in their parking lot, pass and go on with my life.
If anyone has had some experience with WOT causing misfires and limp mode I'd appreciate the input,
Final thoughts and information, I have a 2.5" catback to 2" Y pipe, I have also considered it may be a cracked O2 sensor if they are on the bottom of the J-pipe somewhere as I also have suspension.. but to be quite honest I've never really remembered to look at it over the years.
Thanks for any input!
Last edited by ejreams; 02-19-2020 at 11:40 AM.
03-05-2020, 04:27 PM
#3
Hey, I haven't really posted a whole lot on here, in high school I was on 6thgenaccord all the time, it was my first car.
Anyway, I mean to preemptively apologize if this thread isn't in the correct place and if this has been solved, I've looked believe me.
Short summary, it's a 2003 CL-P years ago I had a coil pack die in a parking lot, I limped it home and by the next day got all of them replaced with OEM packs.
At some point near that time I've had an issue with WOT where the car (around 70mph @WOT) almost always loses power instantly and drops to 3000rpm bogging as if it's in limp mode.
Not shortly after noticing this I replaced all of the spark plugs, didn't seem to resolve the issue, every time this happens it throws P0300 random misfires w/ different cylinders.
I know this may sound like a terrible thing to do; but if I let off the throttle and coast, turn the key to the off position WHILE the car is rolling and bogging and then turn it back to on position the CEL stays but the car stops bogging at 3k rpm as if resetting the ECU directly afterwards takes it out of limp mode.
If I get back on it WOT it happens again 90% of the time.
I also had an issue the last couple years with the car not starting when hot or cold, randomly, etc which I eventually resolved after concluding it was the Main Relay (fuel pump not being powered on properly) which I thought potentially this was a long term side effect of that relay but the issue still exists and is still easily reproduced.
Every time I go to get emissions tests I just reset the battery in the parking lot to drop the codes and obviously don't WOT in their parking lot, pass and go on with my life.
If anyone has had some experience with WOT causing misfires and limp mode I'd appreciate the input,
Final thoughts and information, I have a 2.5" catback to 2" Y pipe, I have also considered it may be a cracked O2 sensor if they are on the bottom of the J-pipe somewhere as I also have suspension.. but to be quite honest I've never really remembered to look at it over the years.
Thanks for any input!
Anyway, I mean to preemptively apologize if this thread isn't in the correct place and if this has been solved, I've looked believe me.
Short summary, it's a 2003 CL-P years ago I had a coil pack die in a parking lot, I limped it home and by the next day got all of them replaced with OEM packs.
At some point near that time I've had an issue with WOT where the car (around 70mph @WOT) almost always loses power instantly and drops to 3000rpm bogging as if it's in limp mode.
Not shortly after noticing this I replaced all of the spark plugs, didn't seem to resolve the issue, every time this happens it throws P0300 random misfires w/ different cylinders.
I know this may sound like a terrible thing to do; but if I let off the throttle and coast, turn the key to the off position WHILE the car is rolling and bogging and then turn it back to on position the CEL stays but the car stops bogging at 3k rpm as if resetting the ECU directly afterwards takes it out of limp mode.
If I get back on it WOT it happens again 90% of the time.
I also had an issue the last couple years with the car not starting when hot or cold, randomly, etc which I eventually resolved after concluding it was the Main Relay (fuel pump not being powered on properly) which I thought potentially this was a long term side effect of that relay but the issue still exists and is still easily reproduced.
Every time I go to get emissions tests I just reset the battery in the parking lot to drop the codes and obviously don't WOT in their parking lot, pass and go on with my life.
If anyone has had some experience with WOT causing misfires and limp mode I'd appreciate the input,
Final thoughts and information, I have a 2.5" catback to 2" Y pipe, I have also considered it may be a cracked O2 sensor if they are on the bottom of the J-pipe somewhere as I also have suspension.. but to be quite honest I've never really remembered to look at it over the years.
Thanks for any input!
1. MAP sensor is faulty
2. Upstream O2 sensor has a slow response
3. TPS sensor is out of range at WOT
4.VVL is not actuating correctly
The CEL will only come on with a 20%+/- variation. There's something causing the issue, but it's not enough of an issue to trip the code for it. There may also be a problem with the transmission kicking down gears at WOT.
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