Rear O2 CEL Warning - Ecuflash Fix Step by Step

[_Biggles_]

How to fix your ECU to remove rear O2 sensor checks and CEL warnings after de-cat.

Hi Ladies and Gentlespoons. Many of us have had a decat. Some choose to fix the CEL indication by use of a special spacer or O2 simulator. Well i found O2 simulation too complex and fiddly to wire, the cel fix spacer from the states fouls the underbody on long journeys as the exhaust expands.

There has to be a better way.....

And yes there is! Been working with grayw today to eliminate the checks for the rear O2 sensor on a standard ECU. Today i can report thats now been fixed!!

So if _Biggles_ the ECU noob can do this, so can anybody.

OK you do have a list of bits to acquire so heres the list:

• Laptop : DUH yep no laptop no ECU chatting, beg borrow, try not to steal
• Limitless or Tactrix Cable : So those can be gotten from Grant @ Gizzmo Electronics (support your MLR trader!) or Limitless themselves
• Ecuflash : Superb FREE software you are going to love forever after today acquired from www.openecu.org
• Aktivematrix ECU Unlocker : Some ECU's are locked after tuning. BOO! This unlocks them. Go to www.aktivematrix.com, sign for free account, download it!
• ROM Definition File : Different for every evo, but go to openecu.org and hit the forums they are all there! Look for your vehicle, if you are struggling to find it, make a post, someone will help you pick the right one!
• You might also wish to consider Mitsulogger or Evoscan as well, you can check for knock etc with those! Evoscan is not free but its excellent. Useful for checking your engine & map health

So thats your parts and software list! Got it all? OK lets get on with fixing the CEL warning once and for all!

[_Biggles_]

OK so first things first, time to set up Ecuflash. So find the file you downloaded and open it. It will be zipped, i used WinRAR to decompress this. The double click the .msi file to get going and install ecuflash

note the pic is for showing you what unzipping looks like here im unzipping evoscan as an example

[_Biggles_]

Before you continue any further, note your ECU may be locked out! So this is where the AktiveMatrix software comes in. Open the zip file and double click the unlocker. A little box like this pops up, just leave it running there in the background to do its magic.

Heres what that looks like

[_Biggles_]

OK so thats Ecuflash and the ecu unlocker installed, now you need to sort out your ecuflash ROM definition. Now many are already there but you are best downloading the most up to date definition file from openecu.org
Go to My Computer > Program Files > OpenECU > EcuFlash > rommetadata > Mitsubishi >evo

Cut and paste the ROM definition file there. If you get a file overwrite warning, cancel it! Rename the file in Ecuflash directory and re-copy. OK Done, now when Ecuflash reads your ECU it knows what all the tables are

Now run Ecuflash, you should get a screen THUS:

[_Biggles_]

Now its time to start interrogating the ECU. Before you do anything else, plug the USB cable into the laptop and set up the drivers, they should pop up automatically! Follow the on screen prompts and lick continue anyway regards driver signing for XP, don’t worry they work!

Now under the drivers side dash you should see one white and one black plug. These are the Logging ODB port and flashing ports. ODB black port is used for checking DTC (Diagnostic Trouble Codes), clearing DTC’s and Logging using Mitsulogger or Evoscan. Heres a pic!

[_Biggles_]

We will be using both plugs. Ignition OFF insert the black plug and white plug into their respective ports under the dash. Its fiddly at first but once you been there a few times you don’t need to look to engage.

So thats black plug to black port (an a tactrix cable) , but to be honest they dont fit in each others slots anyway!

Check the cables are right in and then flip the ign on, not accessory, all the way, just don’t start the car! Youll notice the dash lights (AYC) and CEL flashing, don’t worry its normal, thats ecuflash communicating with your car. When everything has stabilised the AYC Tarmac light will flicker longingly at you

I dont have a picture yet, ill edit it in tomorrow.

[_Biggles_]

Right time to read your rom! Not as hard as it sounds, bit scary the first time, but don’t panic.

Simply click the read from ecu button, click OK when prompted, ensure your ignition is ON (NOT ACC position!) and sit back, these are what you will see happening, takes about a minute or less!

[_Biggles_]

OK your original rom is now on your PC! MAGIC!

Turn off your cars ignition.

THE FIRST THING TO DO IS BACK IT UP!

Save it as originalrom.hex and pop it somewhere VERY SAFE! Use the little disk icon to get the prompt to save as.

NOW ADD THIS LINE OF CODE TO THE BOTTOM OF YOUR XML FILE RIGHT BEFORE THE CLOSING </ROM> TAG



<table name="ECU_PEREPHERY2" category="ECUPeriphery" address="fca" type="1D" level="4" scaling="Hex16"/>



This will make a new table in the rom file when you open it allowing you to add a different Rear O2 Check code

Open up your ROM. You will be greeted with this screen. Click the perephery 2 check box, this opens another box with data. THEN click that box once to make sure its selected. Hit the = key once and enter:




0x89D9

[_Biggles_]

Close the window with the little x, hit the save button and resave as nocel.hex. Youll get an overwrite warning, don’t worry click yes.

OK ROM is now ready to go back! See simple and quick isn’t it! So now turn your ignition back on, wait a moment and then click write to ECU. Button is highlighted in the pic!

Now be patient, touch nothing and definitely don’t turn off your ignition or your laptop. Make sure your laptop is fully charged, a shutdown now wouldn’t help very much.....

OK so here is what it looks like flashing and what its like when done. Just like with reading it will tell you when its finished. Turn off your ignition when it is!

[_Biggles_]

OK so the only thing to do is remove your ODB plug and flashing plug. Careful taking out the flashing plug, its got a retaining clip to press in, so dont just yank on it, youll break it!

Test fire your engine now, should fire right up no worries.

OK now its possible, or entirely probable you still have a DTC or CEL light. This needs clearing.

Two options:

If you dont have evoscan, disconnect the battery for 5-10 mins. Done!

If you have evoscan, reconnect the ODB only and switch on the ignition.

Click Display DTC and then Clear DTC.

Turn of the ignition and diconnect the plug, you are done.

Enjoy driving without the CEL lamp guys, I am!

Thanks to grayw for all your help sorting this out with me today! You are a GEM!

In the next installment, we'll be talking about using modified ROM's and the Tephra Mod which has switchable maps, yes switchable maps on stock ecu, valet mode and much more.

[grayw]

Nice write up chap, only thing I will say is sometimes the ECU PEREPHERY tables are not defined in the defination. So you will need to add the following line to you defination.

<table name="ECU_PEREPHERY" category="Misc" address="faa" type="1D" level="4" scaling="Hex16"/>

[_Biggles_]

use excel or dreamweaver or a text editor and just paste it in at the bottom of the xml definition file before the closing </ROM> tag graham?

[grayw]

Yes, wordpad works fine.

[JamieL]

Very well done nice to see guides like this on here for a change

[Gazzacb]

Should be a Sticky this.

Well done Gray/Biggles