Turbo AEM f/ic dirty signal

so apparently there's something called a dirty signal with tacomas and 4runners that is a huge negative factor when trying to tune a AEM fic 6. It basically causes the fic to lose its signal and the engine tries to run off the factory ecu again. In my case- it runs super rich. There has to be physical reisitors wired into the wiring harness. Problem is- they have to be the right size reisitors and the ones I used didn't work. To prevent my long road of trial and error ahead, does anyone know what size reisitors to run? This is all in attempt to not have to buy a full on stand alone. Any.. and I mean ANY help would be greatly appreciated

 

https://www.tacomaworld.com/threads/how-to-aem-f-ic-6-install-tuning-and-help-thread.381830/

 

I am currently working on the EXACT same issue. Which signal are you having issues with? For me the 2.2k ohm resistor on the cam circuit worked just fine.

What I am struggling with is the 10k ohm resistor on the O2 sensor, it seems like it is not allowing a voltage to be picked up by the FIC6. I first tried the 10k ohm resistor but thought it was too much so I stepped down to a 2.2k, which initially worked but would occasionally not pick up the voltage at start up so I then tried a 1.5k, and now a 1k ohm resistor all with no voltage being picked up by the FIC6.

The over at 4runner.org seems to have the most info.

 

@Brice @Clay_916

 

To avoid having to click a link.

I used a 2.2k ohm resistor across the cam signals.

I also used a 10k resistor on the o2 thing.

However the ECU doesn't try to run like stock if it has dirty signals, it just wont run very well, causing backfires and bucking since the ECU doesn't know where the cam is in relation to the crank and pistons. Also do you have aftermarket injectors? I would also try using the bypass harness that comes with your F/I C6 to make sure you wired it correctly.

 

I didn't use the cam filter. Only the o2 sensor resistor. Like Brice said a faulty cam signal would screw with timing, you'd have misfires. If your are running rich it's likely something else.

If you guys were running fine before and now rich you need to adjust your tune for the increasing temperatures. In my case, the MAF does not compensate enough for changes in temperature. I had to recalibrate my fuel map.

 

You guys had no issues with the 10k O2 sensor resistor huh? Mine doesn't seem to like it because it won't come out of open loop mode. I could get it to work with a 2.2k but I still don't think it was totally right because the trucks AFRs were real lean and bouncing all over in vacuum, out of anywhere I had tuned.

Im wondering if a old O2 sensor would cause a weak signal or something?

 

Possibly, I would try more resistors since (unfortunately) every truck is different. I know the 10k worked and the 2.2k is also working. At first I had a 1.9k across my cam signals but it wasn't enough and I was getting a code along with high rpm backfires. Also are you sure you have a narrow band? I had an issue with thinking I had a wideband at first.

Check this to be sure
http://urdusa.com/store/Denso-Products-Oxygen-/-AFR-Sensors/c204_13/index.html
You'll have to search the PT# to be sure

 

Are you reading voltages from the fic or just assuming it's not working? It should be pretty easy to dial in the right resistor by reading the fic. If the offset value you have set in your o2 map isn't matching the o2 in and out signals then you need a different resistor.

When you say it's in open loop do you just think it is because it's rich or are you actually reading the ecu is in open loop from and obd2 scanner? O2 sensors regulate fuel trims they don't have any say on open or closed loop.

 

Clay,
Yes, I am watching the open/closed loop on my scan gauge and I am reading the voltage from the o2 Bank 1 in the FIC gauge display.

What do you mean by "o2 in and out signals"? Where can I see those?

This just made a light bulb go on in my head. Your right the o2 sensor isn't causing it to stay in open loop, the FIC just isn't picking up the signal when its in open loop because the Factory ECM doesn't use the o2 sensor in open loop mode... Duh.

 

The fic software should show the incoming o2 voltage as well as the skewed offset.