l2r99gst

iTrader: (2)

First of all, the credit for this goes to mrfred. He created this patch for his ROM and I simply applied what he did to the 96940011 ROM. You can read what mrfred did in post #148, page 10 of this thread: https://www.evolutionm.net/forums/sh...268138&page=10

What this patch does is allows you to simulate the rear O2 signal so that the ECU will not throw any CEL codes like the P0420 or P0421 for cat efficiency. So, you can run a test pipe or high flow cat and not have to worry about getting a CEL. This is basically an ECU fix for the common used anti-fouler mechanical fix, if you are familiar with that. As you may know, you can also disable your rear O2 in the ECU periphery, but then your readiness tests for cat efficiency and rear O2 would not run and you would fail OBD II emissions testing. This patch takes care of all of that.

I chose to make a separate thread about this ROM because although tephra's V5 patch includes a rear O2 sim, 96940011 looks like it will not be able to be part of the V5 patching due to space restrictions in this particular ROM. There just isn't enough free space for tephra to work with. So, in the meantime, people are testing other ROMs to work with the USDM 05 Evos, but until a ROM is found that will work and can be used by tephra, we can at least have a rear O2 sim, if we need it.


What is written below is for the 96940011 ROM only!!


To apply this patch to your 96940011 ROM, you will need to do the following steps:

1. Add the following to your 96940011.xml file in the ECUFlash rommetadata folder. You should be used to doing this by now, so I won't go into details here.

2. Open ECUFlash and your 96940011 ROM. Scroll all the way down and you will see a new category named Rear_O2. There will be two new tables named Rear 02 Sim Hook-test and Rear 02 Sim Subroutine.

3. Change the data in the tables to match the following screenshots. The image on the left is how your ROM should look stock. The image on the right is how your ROM should look after you are done changing the values. Since the images may be hard to read, I will also type in the values that you should see stock and what you should change them to below. Remember to type in 0x before these values since these are hex values. In ECUFlash, you must first type in 0x to enter any hex data in the cells.




Here are the values from the tables pictured above:

4. Flash to your ECU



Eric

23r0k001

iTrader: (9)

amazing...thanks. Will post results.

l2r99gst

iTrader: (2)

Just want to make sure that you have or will be trying this on rom 96940011. Your description under your avatar says that you have a IX, so I just wanted to make sure.


Eric

crisdawg

iTrader: (1)

so in order to remove the rear o2 completely, would you need to perform the original resistor mod, as well as this rom mod in order to complete the readiness tests and pass emissions?? or do we just need to do this rom mod now?

l2r99gst

iTrader: (2)

If you wanted to remove the sensor completely, you would need to do the resistor mod as well, as noted in the link in the first post.

This patch takes cares of the sensor. The resistor mod takes care of the heater circuit. I'm sure one of the people good at disassembly will be able to patch the ECU for the heater circuit as well, but this patch is only for the sensor readings itself, to do away with the rear O2/cat cells.


Eric

crisdawg

iTrader: (1)

great, thanks!

23r0k001

iTrader: (9)

yes I have 3 guys that have it on the test pipe with fouls and a cel. This is the rom# which corresponds to a 2005 evo8 GSR correct? Please confirm... Thanks!

I have the evo9 we which has the rom# of the originally posted cel fix.

l2r99gst

iTrader: (2)

Yes, this is the ROM for all 05 USDM Evos.

RazorLab

iTrader: (8)

Very nice!

23r0k001

iTrader: (9)

how can I request this same fix for a usdm 2004 gsr (rom#94170015)? Should a new post be added on directly through here?

l2r99gst

iTrader: (2)

If that is one of the roms that tephra is making a v5 patch for, then there will be a rear O2 sim included in the v5 patch.


Eric

23r0k001

iTrader: (9)

I see that TephraV5 mod but its for a rom#94170014 is that the same as the rom#94170015 found in the USDM 2004 EVO8 GSR with the intercooler sprayer?

Also that rom(94170014) posted doesnt seem to have the tables for Rear O2 Sim Hook and Rear O2 Sim SubRoutine when you load it. Any ideas?

scheides

iTrader: (10)

Yay! At least we can get some of the v5 patch this way, thank you l2r99gst!

tvrvic

iTrader: (6)

Awesome work l2r99gst! This is what I really needed from v5! Thanks for your work to port this patch to this... uh unique rom

l2r99gst

iTrader: (2)

You can check with tephra, but I think the 94170014 and 94170015 are interchangeable.

You won't see the new rear_O2 tables in tephra's patch. He just includes the patch his own way, so you don't have to change anything.


Eric