Problem with P0300 code can't figure out what's wrong - EvolutionM - Mitsubishi Lancer and Lancer Evolution Community

Go Back  EvolutionM - Mitsubishi Lancer and Lancer Evolution Community > EvoM Forums > EvoM Newbie / FAQs Forum
Reload this Page >

Problem with P0300 code can't figure out what's wrong

Notices
EvoM Newbie / FAQs Forum New member? Come on in, introduce yourself, and get acquainted with the evolutionm.net posse :) FAQs will also be answered in here.

Problem with P0300 code can't figure out what's wrong

Reply

 
 
 
Old Jan 12, 2012, 02:22 PM
  #1  
Newbie
Thread Starter
 
Join Date: Jun 2011
Location: Omaha Nebraska
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Problem with P0300 code can't figure out what's wrong

Hey i've been trying to fix this p0300 code (random multiple misfire) on my 2003 evo Viii that has 82k miles. (everything is stock) it randomly decides to turn on and off when it pleases. I've replaced the spark plugs and wires, i have not touched the coil packs and i'm planning on changing the crankshaft position sensor unless anyone has any better ideas..


Also, my car is hitting a fuel cut, or some kind of stutter between 65-75 just cruising on the highway... it's highly frustrating, i have to let off the gas and step on it to get going again just for it all to repeat itself. i was told it could be the stock plastic bov... i have no idea if that's right!

Please help! thanks!
Evolcomk is offline  
Reply With Quote
Old Jan 12, 2012, 03:00 PM
  #2  
Evolved Member
iTrader: (2)
 
chrisw's Avatar
 
Join Date: Mar 2003
Location: Santa Cruz
Posts: 2,218
Thanks: 0
Thanked 0 Times in 0 Posts
this:

https://www.evolutionm.net/forums/ev...tsb-found.html

it sucks, the easiest thing to do is to turn off the test. Search the ECUFlash forum for info on how to do that.
chrisw is offline  
Reply With Quote
Old Jan 12, 2012, 06:02 PM
  #3  
Newbie
 
EvoVIII_03's Avatar
 
Join Date: Mar 2011
Location: Texas
Posts: 33
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by Evolcomk View Post
Hey i've been trying to fix this p0300 code (random multiple misfire) on my 2003 evo Viii that has 82k miles. (everything is stock) it randomly decides to turn on and off when it pleases. I've replaced the spark plugs and wires, i have not touched the coil packs and i'm planning on changing the crankshaft position sensor unless anyone has any better ideas..


Also, my car is hitting a fuel cut, or some kind of stutter between 65-75 just cruising on the highway... it's highly frustrating, i have to let off the gas and step on it to get going again just for it all to repeat itself. i was told it could be the stock plastic bov... i have no idea if that's right!

Please help! thanks!
That misfire is do to the lack of low compression, low fuel, spark or mechanical problem. We now know that you have random misfire so you have to look at it this way, If you had a misfire on one cylinder then you can suspect that it could be wire/coil, spark or injector. But since it says multiple it could be that your fuel pump is not sending the right amount of fuel to injectors, dirty/clogged fuel filter, or spark that cuts off due to crank sensor.
Hope this helps. I never heard of crank sensor issues yet on evos...so you might want to look into your fuel pressure. Fuel Pressure Regulator also tends to leak on other vehicles. Check it by disconectig the fuel regulator vaccum and if it has fuel on the tip then it is leaking.
EvoVIII_03 is offline  
Reply With Quote
Old Jan 13, 2012, 04:22 AM
  #4  
Newbie
Thread Starter
 
Join Date: Jun 2011
Location: Omaha Nebraska
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Alright thanks! i will scratch the idea of the crank shaft position sensor then. I guess my next step is to order some coil packs and a walbro fuel pump then.

do you have an idea about the fuel cut though just cruising?
i'll also give the fuel pressure regulator a shot too today.

it's really frustrating because my buddy had the exact same problem with the fuel cut cruising and he doesn't really remember what he did besides change out the stock plastic bov for a better one..
Evolcomk is offline  
Reply With Quote
Old Jan 13, 2012, 05:58 AM
  #5  
Evolved Member
iTrader: (6)
 
mt057's Avatar
 
Join Date: Apr 2007
Location: DFW
Posts: 1,509
Thanked 4 Times in 3 Posts
This is a very common problem with an easy fix if you have a tactrix cable.

Search for disable p0300 test. There is a thread on here that talks about the code and how to disable it. I used to get the code and enter limp mode in the highway during gentle cruise every 30 seconds or so. I would see my after spike the car would rumble and have no power. A p0300 code would be thrown.

After disabling it, I have not thrown the code again. Nor has my car gone into limp mode. It has been years.
mt057 is offline  
Reply With Quote
Old Jan 13, 2012, 02:17 PM
  #6  
Newbie
Thread Starter
 
Join Date: Jun 2011
Location: Omaha Nebraska
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Thumbs up

Awesome!!!! that is exactly what is happening to my car! i will have to invest in a tactrix cable i keep hearing tons of good things about it. (i hope it works with mac..)

Thanks a lot man that was great advice! i just hope it works... because i'm sure you know how frustrating that can be when you're just trying to cruise down the highway and you cant.



Originally Posted by mt057 View Post
This is a very common problem with an easy fix if you have a tactrix cable.

Search for disable p0300 test. There is a thread on here that talks about the code and how to disable it. I used to get the code and enter limp mode in the highway during gentle cruise every 30 seconds or so. I would see my after spike the car would rumble and have no power. A p0300 code would be thrown.

After disabling it, I have not thrown the code again. Nor has my car gone into limp mode. It has been years.
Evolcomk is offline  
Reply With Quote
Old Jan 22, 2013, 02:52 PM
  #7  
Newbie
iTrader: (7)
 
Join Date: Jul 2011
Location: Wichita, KS
Posts: 68
Thanks: 0
Thanked 0 Times in 0 Posts
I am having this issue as well now. It started on the highway...I was cruising along and just got an immediate power loss, but once I let off the gas i was able to push it up again.

In my case though this happened after about two weeks of having slow starts. Im not sure if that makes a difference at all. Does constantly having slow starts wear on the spark plugs at all? If so, i may just need to change those. Havent actually looked to see if they are fouled or not.

I did check the EGR and everything is fine there
Travenport is offline  
Reply With Quote
Old Jan 22, 2013, 03:30 PM
  #8  
Evolving Member
 
rburris28's Avatar
 
Join Date: Apr 2004
Location: Western North Carolina
Posts: 303
Thanks: 0
Thanked 0 Times in 0 Posts
It is likely the P0300 Multiple Misfire gremlin as noted above.

I mounted Toyo RA-1s and shortly thereafter got the code and fuel cut with 18:1 AFRs, only on the highway at about 7000 rpm in 5th. I replaced the wires and plugs since the car had over 60,000 miles on it. No help.

It returned so bad on the way to VIR I thought I wasn't going to get there. Once at the track, I drove over 4 hours in 2 days at speed without and issue, then it returned on the way home.

Search for the xml to remove checking for the code, fire up ECUFlash, and turn the ability to check for the code off. I did it 15,000 miles ago and no issues since.
rburris28 is offline  
Reply With Quote
Old Jan 22, 2013, 05:13 PM
  #9  
Newbie
iTrader: (7)
 
Join Date: Jul 2011
Location: Wichita, KS
Posts: 68
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by rburris28 View Post
It is likely the P0300 Multiple Misfire gremlin as noted above.

I mounted Toyo RA-1s and shortly thereafter got the code and fuel cut with 18:1 AFRs, only on the highway at about 7000 rpm in 5th. I replaced the wires and plugs since the car had over 60,000 miles on it. No help.

It returned so bad on the way to VIR I thought I wasn't going to get there. Once at the track, I drove over 4 hours in 2 days at speed without and issue, then it returned on the way home.

Search for the xml to remove checking for the code, fire up ECUFlash, and turn the ability to check for the code off. I did it 15,000 miles ago and no issues since.
know anything about if having a long start for a period of time fouls the spark plugs?
Travenport is offline  
Reply With Quote
Old Jan 22, 2013, 07:19 PM
  #10  
Evolving Member
 
rburris28's Avatar
 
Join Date: Apr 2004
Location: Western North Carolina
Posts: 303
Thanks: 0
Thanked 0 Times in 0 Posts
Non starting issues should not affect the spark plugs in any way that will cause the misfire code only on the highway as I described. If you are having issues with the P0300 code and it only occurs at certain speeds and steady throttle, but not under boost or idle, I'd say you have this same problem, which is apparently caused by driveline harmonics. If you're having starting issues, multiple misfires under acceleration or at idle, and fouled plugs, it is probably another issue. Most of the driveability problems the P0300 code causes is due to fuel cut. This should not affect the plugs, nor should weak spark or inadequate fuel at startup.
rburris28 is offline  
Reply With Quote
Old Jan 22, 2013, 07:23 PM
  #11  
Newbie
iTrader: (7)
 
Join Date: Jul 2011
Location: Wichita, KS
Posts: 68
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by rburris28 View Post
Non starting issues should not affect the spark plugs in any way that will cause the misfire code only on the highway as I described. If you are having issues with the P0300 code and it only occurs at certain speeds and steady throttle, but not under boost or idle, I'd say you have this same problem, which is apparently caused by driveline harmonics. If you're having starting issues, multiple misfires under acceleration or at idle, and fouled plugs, it is probably another issue. Most of the driveability problems the P0300 code causes is due to fuel cut. This should not affect the plugs, nor should weak spark or inadequate fuel at startup.
thanks man. good info
Travenport is offline  
Reply With Quote
Old May 6, 2013, 08:13 PM
  #12  
Newbie
iTrader: (1)
 
Join Date: Jul 2011
Location: apple valley
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
:h elpme:hi i am having the same p0300 problem....every time i get on the freeway and every now and then it pops up... i was getting my car smogged and it popped up at last min....almost pass...my question is if i get this code erased from a ecuflash is it going to effect my somg when i go get a retest thank you for your help
mannysEVO is offline  
Reply With Quote
Old May 7, 2013, 04:00 AM
  #13  
Evolving Member
 
rburris28's Avatar
 
Join Date: Apr 2004
Location: Western North Carolina
Posts: 303
Thanks: 0
Thanked 0 Times in 0 Posts
My car has passed for years in NC with the P0300 code testing disabled. I don't think that there is any way for the machine to test if the software works or not, just if it throws the code.
rburris28 is offline  
Reply With Quote
Old May 7, 2013, 01:03 PM
  #14  
Newbie
iTrader: (1)
 
Join Date: Jul 2011
Location: apple valley
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by rburris28 View Post
My car has passed for years in NC with the P0300 code testing disabled. I don't think that there is any way for the machine to test if the software works or not, just if it throws the code.
OK thanks I'm gonna have to try that then.....I'm in CA and they just started this new STAR smog.... I don't know much about it.....I just need to pass this smog
mannysEVO is offline  
Reply With Quote
Old May 8, 2013, 08:07 PM
  #15  
Newbie
iTrader: (1)
 
Join Date: Jul 2011
Location: apple valley
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
anyone is socal that can do the ecu flash to disable the p0300 code for me i will travle a lil and have some cash let me know as soon as you can thank
mannysEVO is offline  
Reply With Quote

Thread Tools
Search this Thread
Quick Reply: Problem with P0300 code can't figure out what's wrong


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.