I have an evo 9 and its running a v1 AEM EMS and im going to be switching over to a stock ecu. it also has a 3 port mac boost solenoid an AEM 3.5 bar map sensor and a IAT sensor (not sure of brand. It looks like all of those sensors r soldered in to the wiring harness are they wired in to the ecu the same way as a stock ecu or do they run to a different spot on the ecu bc its an AEM? Can i run all of the sensors for the stock ecu speed density or do i have to get different sensors? Also my wideband is wired in to the ems does that have to be changed and im also only running one o2 sensor and that's for my widebamd sense im going to b running a stock ecu do I have to run another o2 sensor somewhere? I know its kind of confusing but any help would be great thanks.

 

I'm doing the same swap and have gotten no good answers.

 

I hope this doesn't turn out to be a trial and error thing.

 

I don't understand how no one knows. Even in previous threads there are no answers. I've searched over and over again.

 

Try making the OP a little more readable as well. More people will read it.

 

Im not 100% sure for the 9 but I have a 8 with a v1 AEM and I have to switch out the pin for the wideband in the front O2 (pin 76 on the 8). Also my AEM map sensor and iat sensor are wired right into the same pigtails as the stock ones. I just unplug the AEM sensors and plug the stock ones back in and swap the pin to convert to stock ecu. Not sure if that helps at all

 

Ok thanks. But can I use the same MAP sensor and IAT sensor I have now for the stock ecu bc the pigtails for those sensors r wired in to the wiring harness I don't want to have to solder new pigtails in.

 

Hey man,

I got some answers on my thread:
https://www.evolutionm.net/forums/ev...ck-ecu-sd.html

 

Awesome im going to check that out thanks alot

 

Back from the dead... any updates on whether or not another o2 sensor will need to be installed or will the pin swap from the ems to stock ecu pins work? I am also in the same boat now
Sorry for the bump but I am looking for answers lol

 

As was said in this thread ^^



The first highlighted statement: is there a certain knock sensor you have to use with the stock ecu? I have a knock sensor on my AEM and if I can use that with the stock ecu that would be great.


The second: I find this super hard to believe. I have messed with my start up so much I can't possibly figure out how to make it crank in 2-3 revs every time in cold to hot conditions. It's especially crap in the cold. My AEM will frequently take 6-7 tries before it will start and idle if its less than 30* outside and then usually when I do get it to finally idle it will die at the stop sign so I have to go into my advanced idle and bump up the whatever table so that the "learned idle" isnt having to add or subtract from the value currently in it.*


I'm so sick of HAVING to carry a laptop with me everywhere I go and take 5 mins to make the car idle EVERY time the weather changes 5* its the worst thing ever when you find out your car won't idle, your laptop battery is dead, and you've left your power cable at home..


I have never read about a stock ecu having these issues.

That having been said I realize that post is over a year old and maybe they hadn't fixed that stuff yet or maybe he was just talking about the stock ecu in SD?

I also just realized this post turned into a rant but I am really biased against this turd of an ecu anymore

 

In regards to the 02 sensor: The stock ecu cannot read a widebands output(some small exceptions via mrfreds patched rom). What you need is either a wideband that can do narrowband simulation or a narrowband sensor. Without this your car will not be able to go into closed loop idle/cruise or calibrate your fuel trims. You will need to wire the narrow band simulated output into the factory pre-cat narrow band pin on the ecu. You will also need to apply some patches to eliminate 02 heater cel codes from popping up if you dont have an actual narrow band hooked up somewhere. Check out the ecuflash subforum its all there.

 

I appreciate the info. Seems like wiring in the stocker will make most sense. Easiest thing to do. I will however look into the ecuflash subforum for more info. Thanks again.

 

Sorry guys I have been meaning to post some info in this thread but forgot about it.

So I did end up installing the stock ecu back into my car and I had everything we would well. I used my wideband (NGK AFX) which only gives out an analog signal 0-5volts. You can hook that up into the stock ecu and have the stock ecu read it. You just have to mod on of the hex files in the stock ecu. (It's been a while since I did that I can't remember what I had to do) then the stock ecu will use the wideband. I also wired in a front stock o2 sensor to help get better afr's while cruising and what not. Other than that the swap from aem ems to stock ecu is easy. I just used a omni 4 bar instead of the aem 5 bar I had and the IAT sensor I replaced with a gm (the aem IAT sensor is the same) because mine broke.

If u have any other questions I can true and help.

 

Were you using the factory resistor pack with the aem or did you have to swap it back in?