Evo 8 SES Light
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Newbie
Joined: Dec 2015
Posts: 16
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From: Santa Barbara, CA
Evo 8 SES Light
Hi guys,
Just picked up an Evo 8 last week (05) after selling my 11 WRX. With the Subaru platform we could use an Accessport to remove the check engine light codes from being catless.
This Evo has the SES light on, I am told from being catless. I need to get the car smogged to register it in California and I am unsure of the 'best' way to get light off so it passes the readiness test. I'd like to avoid putting the cat back on as I have very little tools to do it myself here at college and would hate to have to pay a shop to do it.
Any insight is appreciated. I did see things about drilling into an 02 bung etc, but again I have few tools here. A friend of mind suggested a tool that connects to the wiring that fools the ECU, can anyone recommend a specific brand and what specifically this would be called?
Thank you!
Just picked up an Evo 8 last week (05) after selling my 11 WRX. With the Subaru platform we could use an Accessport to remove the check engine light codes from being catless.
This Evo has the SES light on, I am told from being catless. I need to get the car smogged to register it in California and I am unsure of the 'best' way to get light off so it passes the readiness test. I'd like to avoid putting the cat back on as I have very little tools to do it myself here at college and would hate to have to pay a shop to do it.
Any insight is appreciated. I did see things about drilling into an 02 bung etc, but again I have few tools here. A friend of mind suggested a tool that connects to the wiring that fools the ECU, can anyone recommend a specific brand and what specifically this would be called?
Thank you!
EvoM Community Team Leader
Joined: Aug 2005
Posts: 5,690
Likes: 708
From: West Coast
Your not going to pass smog in California without the cat. As far as the light goes, you should check and see if you have any local evo meet ups and try and get some help from someone with ecuflash. Go spend some time on the ECUflash sub forum if you would like to know more. Hint there is a sticky with all the important ecu threads, look for the threads regarding passing emissions testing.
Thread Starter
Newbie
Joined: Dec 2015
Posts: 16
Likes: 0
From: Santa Barbara, CA
Your not going to pass smog in California without the cat. As far as the light goes, you should check and see if you have any local evo meet ups and try and get some help from someone with ecuflash. Go spend some time on the ECUflash sub forum if you would like to know more. Hint there is a sticky with all the important ecu threads, look for the threads regarding passing emissions testing.
Definitely will look into the ECUFlash...thank you!
Newbie
Joined: Oct 2015
Posts: 62
Likes: 1
From: Arizona
I just went through the same situation. Bought the car a few months ago, the PO gave me the stock exhaust but I didn't want to go through the trouble to swap the entire exhaust out. I plan to get the Tactrix cable and do some tuning which lets you program out the rear O2 stuff. Due to timing and budget I couldn't pull that off quickly enough.
I tried a few tricks I found on the internet, installing a resistor and a cap that supposedly worked for some Toyota guys. Anyway, none of those things worked for me.
I still have the rear O2 so I used it and wrote a program for an Arduino and was able to modify the signal successfully to get it to clear the codes. Leaving the OEM rear O2 in keeps the heater code off. If you don't have the OEM rear O2 sensor it will also work by pulling the signal from the front O2 sensor, processing the signal, and outputting it to the rear O2 sensor input to the ECU. Without the rear O2 you'll need to simulate the heater circuit which I did with a 75 ohm 25 watt resistor mounted to a heat sink. It didn't get super hot but to be safe I used the heat sink.
Basically what the program does is watch the normal O2 signal, front or catless rear sensor, which rapidly swings between about 100mV - 900mV. It takes 50 sample readings, averages it and outputs that signal back to the rear O2 input at the ECU. The processed signal matches what the ECU is expecting. After this mod and driving a few times and after about 24 hrs, all the ready tests were complete and I got a "No Codes - Ready" status from the ECU. Haven't seen that since I bought the car.
I was going to do a more extensive write up of how to do this but haven't had a chance yet. I normally have a wide band O2 in the rear spot but put the OEM one back in while I sorted out the SES light. I will be pulling it and using the front signal and the resistor on the rear heater input, at least until I get my Tactrix cable and can tune it all out so I can put my wideband back in.
Do you know what specific SES code(s) you are getting? If it's only P0420 this will do it. If you also have the rear O2 heater failure code, P0141 I think, that probably means you don't have an OEM rear O2 sensor at all and you'll have to do the resistor and use the front O2 signal. Not sure your experience level with electrical but this is actually easier than it sounds. Arduino UNO's are pretty cheap and the wiring isn't too difficult. I did all of mine under the front passenger seat as that is where the O2 sensor wiring comes into the cabin.
Let me know if you want to have a go at this and I'll get you some more information. Let me now if you need to use the front O2 signal or can use the rear O2 sensor (assuming you still have one).
Oh, and this should be moved to the tuning or electrical forum, see the note at the top of the page...
Shane
I tried a few tricks I found on the internet, installing a resistor and a cap that supposedly worked for some Toyota guys. Anyway, none of those things worked for me.
I still have the rear O2 so I used it and wrote a program for an Arduino and was able to modify the signal successfully to get it to clear the codes. Leaving the OEM rear O2 in keeps the heater code off. If you don't have the OEM rear O2 sensor it will also work by pulling the signal from the front O2 sensor, processing the signal, and outputting it to the rear O2 sensor input to the ECU. Without the rear O2 you'll need to simulate the heater circuit which I did with a 75 ohm 25 watt resistor mounted to a heat sink. It didn't get super hot but to be safe I used the heat sink.
Basically what the program does is watch the normal O2 signal, front or catless rear sensor, which rapidly swings between about 100mV - 900mV. It takes 50 sample readings, averages it and outputs that signal back to the rear O2 input at the ECU. The processed signal matches what the ECU is expecting. After this mod and driving a few times and after about 24 hrs, all the ready tests were complete and I got a "No Codes - Ready" status from the ECU. Haven't seen that since I bought the car.
I was going to do a more extensive write up of how to do this but haven't had a chance yet. I normally have a wide band O2 in the rear spot but put the OEM one back in while I sorted out the SES light. I will be pulling it and using the front signal and the resistor on the rear heater input, at least until I get my Tactrix cable and can tune it all out so I can put my wideband back in.
Do you know what specific SES code(s) you are getting? If it's only P0420 this will do it. If you also have the rear O2 heater failure code, P0141 I think, that probably means you don't have an OEM rear O2 sensor at all and you'll have to do the resistor and use the front O2 signal. Not sure your experience level with electrical but this is actually easier than it sounds. Arduino UNO's are pretty cheap and the wiring isn't too difficult. I did all of mine under the front passenger seat as that is where the O2 sensor wiring comes into the cabin.
Let me know if you want to have a go at this and I'll get you some more information. Let me now if you need to use the front O2 signal or can use the rear O2 sensor (assuming you still have one).
Oh, and this should be moved to the tuning or electrical forum, see the note at the top of the page...
Shane
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