I don't get it either. Explain what you are talking about with the ses light. Maybe the ecu is still reading the misfire, but isn't sending the car into safe mode, so we don't get the stumble? I need a better explanation, but am definitely willing to pay $35 to get rid of the stumble.

 

..

 

Hey man, I don't care if he is John Force or Micheal Shumacher. If you have a fix for something that is afflicting everyone, and you are going to post it where the world can see it, why only help those who can drive to see you? That doesn't sound selfish to you? Unbelievable. I'm sorry you have it out for me, but I am not speaking for myself. There are a lot of people who want this code fixed that don't live next door to Nate. Stop deleting my 2 cents because you have a personal problem with me. Communicate with me on PM like I keep trying to do with you and stop showing how you feel about me on the public forums. I would really appreciate that.

I never even said I wouldn't pay to have my light fixed or for how to fix it. My only gripe was why he only offers help to a few, when many have the problem. Stop making mountains out of my molehills.

 

Hasn't the dealership flash fixed this or was that for something else?

 

The dealerships apparently had a flash or solution to this but it has also reportedly not worked on many cars who have tried it. I would love to get to the bottom of this. I may look at what access is like tonight to my knock sensor and put some teflon tape on to see if that helps. I'll post up results. Otherwise, has anyone else looked into this?

 

Nate, if the misfire is fixed, why does the light still come on? I was also under the impression that this isn't actually indicitive of a misfire, but rather a software problem giving a false CEL without a misfire. Is this why you want to look at the code?

 

Evotexas,
I don't want to look at the code to see why it's giving a false misfire; I already suspect that the random misfire is caused by either too "tight" of a calibration window for the camshaft position sensor, Mitsu's own code running the car too rich, or stuff like aftermarket cams of bigger fuel pumps supplying more fuel that the ECU expects to see, and it just "suspects" a misfire, so it throws the code. I want to see the code so I can attempt to figure out how to change it so that it just doesn't throw the SES light on even if it just "suspects" that misfire condition. It's been done before, so there shouldn't be any reason why it couldn't be done again.

I think since there seems to be a difference in the severity that different cars are affected by the Random Misfire code, some getting the actual misfire, and some just getting the SES light, some cars would still get the SES light after this little fix, but if the car didn't start out with the misfire, and just had the SES light, it would probably take the light out if that is all the person is worried about. I wouldn't personally do the fix if it was just to get rid of the light, I would only do it if they're getting that really annoying misfire condition during cruising.

 

Sorry for the double post, but I didn't answer Sir Lurks Alot's question about clearing the code.

The car I did the fix on got scanned last night at Turbotrix, and when the cleared the SES light, it came right back, but this time not for the RM code, this time it was something else that didn't seem to affect the performance, but the light was still on. They tried making some changes to what I'd done in an effort to both eliminate the misfire and clear the code, with some success, but the car's owner called me on his way home to let me know that after the changes the car misfired a little bit. He said he was going to undo the changes that were made and go back to just not having the misfire. I guess it's an ongoing testing process at this point as far as getting the light to go out, but the owner said that before they messed with it, the car hadn't misfired once since I did the fix.

 

So it sounds like whatever you are changing is software and not hardware. Would this thread help any?

It basically says that it is clearly random and not related to modification (fuel pumps and cams). Let me know if that changes anything.

https://www.evolutionm.net/forums/sh...ighlight=p0300

 

I've had this code for a while and didn't start experiencing it till I had an issue with my crank angle sensor. I believe my issues are with my crank angle sensor but the whole issue with DSM's previously was with the resolution of the CAS. The ecu expects it to be within certain specs. What he is referring when he says too "tight". He is probably hacking the harness to trick the ecu. I've been too busy with work lately to do any testing and haven't gotten my scanner to see anything. So realize this hack is not the answer. The ECU code would be the real answer BUT hey anything that works.


bryan

 

Why are so many bone stock cars setting it off?

 

All I can think of is a batch of bad crank angle sensors, cam angle sensors or too "tight" of tuning on said sensors. He might be doing something that modifies the wave form from the said sensors.

bryan

 

Basically the ECU knows when to fire the injectors and plugs by reading the waves generated by the cam and crank angle sensors. If it detects something being out of wack "firing" before the correct signals (crank angle+cam angle) are received then it thinks misfire.

bryan

 

i got the SES over the weekend while i was doing donuts. shut my car down, smelled like a whole lotta fuel... wouldn't start for about 5 minutes. SES went away after i started her up twice.

this isn't related is it? and could anyone tell me more about this if it's not? sorry for the OT post....

 

(Blake Heisler's Fix for misfire Check Engine Lights (CELs) when putting a 1G Cam Angle Sensor (CAS) on a 2G)

Many people using the 1G CAS on a 2G head have been running into problems with misfire engine codes while at cruise. Many different things have been blamed for this and many different fixes have been attempted.

This fix will keep the ECU from looking for misfires at all. This is the criterion that must be met before the ECU will start to look for misfires:

1. 300+ seconds of steady state RPM less than 80% throttle position

2. Engine coolant temperature -10C or higher

3. Intake air temperature -10C or higher

4. Barometric pressure greater than 76 kPa

Now if we can get one of these values outside of the criteria the ECU won’t check for misfires. The value that would be the easiest to change would be the barometric pressure sensor. We’re going to add resistance to this value so that the ECU will see less barometric pressure than what there really is. This will also lean the car out so you should see a performance increase as well. Depending on the car and altitude you might need to add more fuel with an AFC.

So let’s get started, Parts needed:

A 10K potentiometer (although a 5K would probably do just fine). These are available at any electronics store, if you go to Radio Shack ask for a volume control knob because they don’t know what a potentiometer is

Wire strippers

Soldering iron

Step 1: Remove the access panel on the driver’s side of the center console. You should now see four plugs with a ton of wires going to them.

Step 2: Pull out the top plug, it’ll be the one that’s the hardest to reach. Locate wire #85. It’s orange with a white stripe.

Step 3: Cut the orange wire in half. Solder one end of the wire to the center peg of your potentiometer. Solder the other end to either the left or right leg, it doesn’t matter which. Turn your potentiometer all the way counter-clockwise.

Step 4: Plug the harness back in and start up the car. It should sound like it did before you did any modifications. If the idle is choppy or the car won’t run you turned your potentiometer the wrong way.

Step 5: Add resistance to the barometric pressure sensor by slowly turning the knob on the potentiometer. Drive the car around; if you get a CEL then add some more resistance. Keep doing this until you no longer get the CELs.

That’s it, special thanks to Marco for pioneering this mod and to all the guys on the DSM1Gina2G Yahoo group for all the discussion, ideas, etc.

-Blake Heisler

================================================== ======

I believe this might work on the EVO but I believe it might play with the fuel setup. So if you have something similiar to the AFC it could be made up for.

I'll be trying it out soon...


bryan