Has anyone ever gotten a constant CEL, hooked up their OBD2 reader and not gotten a code? I had a constant CEL that is detailed here:

http://forums.nasioc.com/forums/showthread.php?t=657334

I plugged in a friend's reader and got. . .nothing. So we cleared it and I went on my way. The car's running fine and I think nothing more about it. The I get up for work this morning and there's the CEL again. Any thoughts?

What type of reader/scanner was it? Some of the generic OBDII readers may not be able to interpret certain mfr.-specific codes. You may need to have it scanned at a dealer with a Subaru Monitor, or find someone with a scanner that understands Subaru-specific codes (my AutoXray does) and try that.

Also, what type of engine management are you running and is there a possiblity the test connectors under the dash got connected? Does the fan turn on and off while the cel is flashing?

jeff

Mulder:
saggioWRX owns the code reader and I have to assume since he owns a WRX and has been using it on his buddys WRX that it is one that reads Subaru codes. I can't confirm that tho. Dave?

Ironlung:
I am running a UTEC, but it's in stock mode as of about a month ago. The CEL doesn't flash and the fan works fine. I'm not sure what specifically you're talking about when you reference "test connectors".

He is referring to the green connectors under the dash that are normally left unplugged. When connected together they activate an ECU diagnostic mode where the CEL flashes and the fans, relays, solenoids etc. cycle on and off.
Most generic code readers will connect to the car (although there are some that won't work with Subarus) and will be able to retrieve many of the possible trouble codes. But it's possible that your car happened to set a code that his unit couldn't read. I know that my AutoXray scanner is programmed with specific data for a number of Asian vehicles including Subaru, but this is not true of all such units.

Mulder:
saggioWRX owns the code reader and I have to assume since he owns a WRX and has been using it on his buddys WRX that it is one that reads Subaru codes. I can't confirm that tho. Dave?

Ironlung:
I am running a UTEC, but it's in stock mode as of about a month ago. The CEL doesn't flash and the fan works fine. I'm not sure what specifically you're talking about when you reference "test connectors".
Hey Bud,
Talking Test Connectors there is also a single pin Black Plug around the same location as the green one, (above the Steering Column over here), that is for 'Memory Re-Call' without a 'Code-Reader'. THIS is the terminal that is connected new and causes the CEL to stay on, (not flash), this for a number of reasons the most obvious being that it stops the Engine from entering 'Cold=Rich' running to avoid fouling S/Plugs in relation to Stop/Start Driving associated with Transit from Japan.......Blah Blah :D


Check this out and see, (who knows, you guys may not even HAVE ONE!! :lol: ).....

Hope this helps,

Sixpack Subaru

It's an (INNOVA 3100 OBDII) Scanner. I pull codes all the time on Subarus.

So I hooked it up at Schucks to their AutoXray and got:

P0113 - Intake air temperature sensor circuit high input
P0037- Rear oxygen sensor heater circuit malfunction

The only mod I have right now is a Perrin Short ram intake. It's been hapily installed for a year and a half with no cels.

The IAT is in the MAF, maybe the intake has affected it?
The 02 sensor code could be a wiring problem, have you driven over/through anything lately that could have damaged it? A visual inspection is in order.

How can I check to see if the MAF has been affected?

Can anyone post a pic of what I should be looking for as far as the 02 sensor goes?

Anyone know what the part# for the rear 02 sensor is? And, can someone point me towards some installation instructions (if it's complicated)?