Retrieving trouble codes from a Subaru WRX (Page 1/3)
Patrick NOV 30, 09:17 PM


I know next to nothing about Subarus, but I've been thinking of checking out a 2002 Subaru WRX advertised locally. However, the seller says the "CEL is on and not cleared due to O2 sensor set off by straight pipe". Apparently he's modified the exhaust. Whether what he says is true or not, I realize that it would probably be quite advantageous to be able to retrieve trouble codes when looking at this or any other car prior to purchase.

Does anyone know if there's a method of retrieving trouble codes on a 2002 WRX without the use of a code reader? We're all familiar with the paperclip trick that's used on our Fieros to get the codes. I'd just like to know if there's a similar procedure to use with this Subaru.

[This message has been edited by Patrick (edited 11-30-2015).]

thesameguy NOV 30, 09:20 PM
You'll need a code reader - there is no way to do it without.
Patrick NOV 30, 09:36 PM

quote
Originally posted by thesameguy:

You'll need a code reader - there is no way to do it without.



It can be done with other years and models of Subaru (as discussed Here). I was hoping there was a similar method for the 2002 WRX.

If not, is there a recommended inexpensive OBD2 code reader... or a cable/software package to be used with a laptop (similar to using WinALDL on our Fieros)?
1988holleyformula DEC 01, 12:29 AM
Hey Patrick, thanks for the PM and subsequent e-mail notification. Haven't visited PFF in forever, I kinda miss it!

As for your Subaru situation, can't say that I'm able to offer much help. I don't think there is an easy way or trick to check the codes, at least none that I ever knew about. I can say that my bugeye with its far from stock exhaust would commonly throw me the O2 code, that I would just double check every once in awhile since a friend of mine works in an auto garage. Only once did it actually need the sensor replaced (not cheap!), but it was running and idling like crap at that time so I knew something was up.

Silicoan86 on here is actually the one that built my little 300hp AWD fun machine, so he might be able to tell you more if he's still around. I unfortunately had to sell my bugeye awhile back and ended up buying my first house. I just couldn't afford the insurance costs associated with a WRX coupled with my speeding tickets. I still have my '88 Formula, but my daily driver is about as bland as they come...



Anyways, sorry for going so off topic, just feels good to post of PFF again. I'll have to visit here more often!
Patrick DEC 01, 12:49 AM

quote
Originally posted by 1988holleyformula:

Silicoan86 on here is actually the one that built my little 300hp AWD fun machine, so he might be able to tell you more if he's still around. I unfortunately had to sell my bugeye awhile back and ended up buying my first house. I just couldn't afford the insurance costs associated with a WRX coupled with my speeding tickets. I still have my '88 Formula, but my daily driver is about as bland as they come...



A Honda? Heh heh...

Thanks Aaron, I'll fire a PM off to Silicoan86.
thesameguy DEC 01, 01:01 AM
If you just want OBDII codes, the cheapest route is probably an ELM327 doodad and a smartphone app like Torque. Plenty of references to that on this forum. $15 buys a Harbor Freight scanner or something like an Autel MS300. If you want something that reads other systems (like, say, ABS) or gets manufacturer specific codes, cost goes up quickly.
Silicoan86 DEC 01, 01:52 AM
Oh man, it's been years since I've messed with a WRX.

You'll need an OBDII scanner to check the codes.

If he's messed with the exhaust (specifically the catalysts), he should have had the car tuned (or ecu reflashed with an off-the-shelf map at a minimum). These cars are rather sensitive to mods and really should be tuned properly when modded to prevent issues. Do some research on the Subaru forums (nasioc, mnsubaru is a local one to me but is a good resource, etc.) to see what the side effects can be of a poorly tuned/modified WRX.

I'd ask if he had any tuning done (and if so, by who) when he did the mods. Judging by the CEL, my guess is no.


BTW...

quote
Originally posted by 1988holleyformula:
Silicoan86 on here...



Hi Aaron!!
Patrick DEC 01, 02:08 AM

quote
Originally posted by thesameguy:

If you just want OBDII codes...

If you want something that reads other systems (like, say, ABS) or gets manufacturer specific codes...



You bring up a good point that there's more than just OBD2 codes.

I'm a dinosaur and don't use a cell/smart phone of any sort , so that kind of rules out some of the devices. I'd like to find a cable that I could plug into my laptop.



That pictured item is supposedly for an Audi, but I haven't discovered yet if there's something similar (with appropriate software) for a 2002 Subaru WRX.
Patrick DEC 01, 02:18 AM

quote
Originally posted by Silicoan86:

You'll need an OBDII scanner to check the codes.



I'm beginning to get that idea.


quote
Originally posted by Silicoan86:

If he's messed with the exhaust (specifically the catalysts), he should have had the car tuned (or ecu reflashed with an off-the-shelf map at a minimum)...



This is what he's done. Looks like the muffler is missing. I haven't seen or heard this car yet.




quote
Originally posted by Silicoan86:

Do some research on the Subaru forums (nasioc, mnsubaru is a local one to me but is a good resource, etc.) to see what the side effects can be of a poorly tuned/modified WRX.



Yeah, I suspect I have a lot of reading ahead of me. Thanks for your response to my PM.
Silicoan86 DEC 01, 02:31 AM
I don't know if it's still the go-to brand these days, but I bought a cable similar to the one you posted above from Tactrix (Google it) for my WRX. Was the go-to brand cable a decade ago, and can be used for reading codes, data logging, as well as tuning/reflashing the stock ECU.

If he's only modified the muffler and left the cats alone, the car is probably fine without tuning. But, if he's only modified the muffler and left the cats alone, the CEL shouldn't be on.