misfire p300 code help
Nov 7, 2010, 07:41 PM
#1
misfire p300 code help
my car started acting up and kept struggling to go. my cel came on i took it to auto zone and it gave the misfire code p0300.i changed the spark plugs ran it for 14 miles then it started again.i changed the coil packs and same thing...any help please.... injectors?? anything?
Nov 7, 2010, 07:46 PM
#2
Wait shouldn't it read p030x? x being 1,2,3,4 corisponding to which cylinder is misfiring. I just had a p0304 code pop up 2 days ago, the plug in cylinder #4 was shot 1.) re-check the gaps to the new plugs, 2.) r u running way to lean at wot? Screwed up tune? 3.) injectors are shot, check your o-rings for cracks.
Paul
Paul
Nov 7, 2010, 07:49 PM
#3
Did you actually have a misfire or did it just through the code and pull timing for a second?
I have had this issue since I bought my 03 3 months ago and have read that it is a very very common occurence. Mine always happens when cruising at 3000rpm (roughly 70mph) about every 240-320 miles. So after some trouble shooting, plug changes, tune I have found my solution..... I don't cruise at or above 3000rpm anymore. It's been roughly 500 miles since the last thrown code and no issues at all.
I have had this issue since I bought my 03 3 months ago and have read that it is a very very common occurence. Mine always happens when cruising at 3000rpm (roughly 70mph) about every 240-320 miles. So after some trouble shooting, plug changes, tune I have found my solution..... I don't cruise at or above 3000rpm anymore. It's been roughly 500 miles since the last thrown code and no issues at all.
Nov 7, 2010, 07:53 PM
#4
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Does it only happen at highway speeds? If so, could be a worn 5th gear synchro causing the knock sensor to pick up the vibration. Mine does this periodically. Always throws the random misfire cel.
Nov 7, 2010, 08:02 PM
#5
this happens at any gear any speed..the choose was p0300 for sure...i have checked the gaps that's why i changed the plugs back to the original ones that didn't have a problem.....im lost do you guys think itcould be my injectors?
Nov 7, 2010, 08:06 PM
#6
Evolved Member
If you own an '03 you most likely will get the p0300 code. Have your tuner turn it off in the ECU. Fixed!
Last edited by barneyb; Nov 7, 2010 at 08:12 PM.
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Nov 8, 2010, 04:54 PM
#12
Evolved Member
It is most likely some play in your transmission that is being transmitted to the engine and being picked up by the crank sensor. You could have the transmission overhauled but the transmission in its current state could last the lifetime of the car if you don't beat on it too hard. The other option is to have this test deleted permanently from the ECU.
Well, you could keep throwing parts at it and getting nowhere.
Well, you could keep throwing parts at it and getting nowhere.
Nov 8, 2010, 05:13 PM
#13
It is most likely some play in your transmission that is being transmitted to the engine and being picked up by the crank sensor. You could have the transmission overhauled but the transmission in its current state could last the lifetime of the car if you don't beat on it too hard. The other option is to have this test deleted permanently from the ECU.
Well, you could keep throwing parts at it and getting nowhere.
Well, you could keep throwing parts at it and getting nowhere.
is there a way too find out the real issue. i just had the clutch installed about 3 months ago.i do have another tranny just in case...our do you think i should just take it to the dealership and find port for sure what it is?
Nov 8, 2010, 05:20 PM
#14
there are lots of threads on this dude. I got flamed a year ago for not searching when i made a thread about it. I had this too. Try remove battery terminals for 10 seconds and start engine, if it runns rough for half a tank of gas (trying to stall and stuff upon idle...) then 2 things that I've gathered with mine
02 sensors shot (do you have any custom exhaust)
and once again as stated, ECU.. usually happens with cam installs but you tell me you don't have aftermarket cams or timing belts or anything to do with cams/lifters.
its not a tranny issue. Don't get freaked out about that. Almost every 03 evo is throwing this code. Don't panic. Just drive with the check engine light on like i do lol
and spend the extra 50 bucks to get a code reader and leave it in the car... you own an evo didn't you know that?! lol. Easy and can be a life saver, trust me.
02 sensors shot (do you have any custom exhaust)
and once again as stated, ECU.. usually happens with cam installs but you tell me you don't have aftermarket cams or timing belts or anything to do with cams/lifters.
its not a tranny issue. Don't get freaked out about that. Almost every 03 evo is throwing this code. Don't panic. Just drive with the check engine light on like i do lol
and spend the extra 50 bucks to get a code reader and leave it in the car... you own an evo didn't you know that?! lol. Easy and can be a life saver, trust me.
Last edited by tundeclips; Nov 8, 2010 at 05:23 PM.
Nov 8, 2010, 05:30 PM
#15
P0300 on this site as old as the 03 that came over to the USDM. Mitsu's answer. 2 updated rom images to help combat the drivetrain harmonics that feedback to CPS causing the code to trigger. Updated roms from 0008 03 roms were the 0014 and 0015 roms.
After that
Hard parts: Plugs, wires, coils, input shaft bearing, aftermarket clutch chatter
Tuning: Idle timing too advanced, large gaps between cells in fuel and timing maps
All checks out? Disable code routine. Never another P0300 issue EVER.
+1 to BarneyB
After that
Hard parts: Plugs, wires, coils, input shaft bearing, aftermarket clutch chatter
Tuning: Idle timing too advanced, large gaps between cells in fuel and timing maps
All checks out? Disable code routine. Never another P0300 issue EVER.
+1 to BarneyB