Electrical load changes afr on o2 gauge during idle
 

Before I start these are the mods I've done to my Scooby.

Changed turbo to TD05-20g,
Unequal length headers plus Decat up pipe,
Hi-flow catted downpipe,
Cat back exhaust,
Short ram Intake,
FMIC,
Decapped 816cc WRX injectors,
3 port boost solenoid.

I'm having an issue with my 04 wrx for sometime now. I have a prosport wideband o2 gauge plus boost gauge that before I started modifying my car used to read 14.7 afr all the time at idle, when ever the electrical load changed. Now for some reason when electrical load is high it stays at 14.7 afr. When the electrical load is low the gauge goes to 14.2 afr. Also my rpm goes up by 50 when load goes up, but when I look at my data logging though romraider my "bank 1 o2 sensor" reads 14.7 what ever the load change is.

At the moment I'm using Romraider & Ecuflash to remap. I've equaled out the Fuel Trims with my Injector Latency Values, so it's not that. I've also changed the "min idle speed high electrical load" down by 50 rpm to soften out the rpm change, but that also hasn't helped the afr change.

So is there anyone out there who has any suggestion on what might fix this dilemma?

are you running the prosport off it's own o2 sensor or bleeding the signal going to the ECU from the front o2? If it's on it's own sensor where do you have them fitted in the exhaust?

Running it off it's own o2 sensor

if you've a bad earth point somewhere depending on where you are getting your power for the gauge/sensor it would give an incorrect reading

Ok, I'll give it a shot & come back to see if that works ��

check battery voltage as well, if your battery voltage is low there is a comp table for that too which will bump the revs up but if your low on voltage the sensor will be hit by that and give a slightly off read.

Was just about to suggest this, it's certainly where I'd start.

Ok. I Changed the ground but still the same. Also got the multimeter out & checked the volts of the battery. It's at 12.44 v. So what comp table in Ecuflash are you referring to?

your looking for "idle target minimum after low battery volts" i think the default is 1000rpm though - it also may not be defined for your rom though with an 04 wrx you should be getting into carberry at some point.

Yea. There's no table for that. I got "min idle speed target a, b" which I changed from 700 to 750, but no change in afr but revs. So put it back to 700 "Min idle speed a/c" at 800 which I left, & "min idle speed high electrical load" which I dropped from 750 to 700, which is my standard revs with no headlights. What's Carberry?

carberry is the open source rom which includes antilag/map switch/launch control etc. once you get your electrical gremlins sorted go check it out:
http://www.romraider.com/forum/viewforum.php?f=36

have you checked your LTV info just to make sure you haven't got any weird leaks going on?

Checked the long term fuel trims. All's good.

Was thinking it could be that the car is pulling timing, coz I've heard some mods cause cars to do this. I might try & see if my Subaru garage can get the timing light to it.

You do realize that the difference between 14.7 and 14.2 is negligible and not worth concerning yourself over ?

^^^ this - plus if your pulling timing you'll see it in romraider logger anyway so shouldn't be any need for a timing light unless your trying to set adjustable cams?

Not putting adjustable cams in. Did have an idea of changing the CL fueling targets. Would any of those might work?

you could be chasing your tail - as Martyn has rightly said the difference is nothing in real world terms. It could even be a simple exhaust leak somewhere enough to change the readings between the primary o2 and your aftermarket one - does your wideband have a calibration option if so you could try that too but I wouldn't start changing things in the map as nothing in the map has changed to cause it.

No probs. Thanks for the help anyway. I'll re-calibrate the o2 sensor, & see what happens.