OBD2 Codes...CAT, O2 Sensor, or Something Else?

Asked by Mar 22, 2012 at 10:29 PM about the 2000 Subaru Legacy L

Question type: Maintenance & Repair

I have a 2000 Subaru Legacy L Sedan.  It died while driving home.  The lights, radio, and power all work, so I don't think it's the battery or alternator.  I checked the belts, and the car has gas and oil.  I borrowed an OBD2 scanner from AutoZone and it pulled these codes: P0328, P0340, P0420, P0031, P0336 (PENDING), P0341 (PENDING), and P0340 (PENDING).  I think P0328 can be disregarded because this code has been on for years (just haven't replaced the Engine Knock Sensor).  How do I know if it's possibly the CAT or O2 sensors, or something else fuel or ignition related?  Any suggestions would be appreciated.  Thank you!

5 Answers

10

usually most P0300 codes no matter the make or model of vehicles seem to be a misfire issue? or at least that is what i have noticed...

What does that mean? Timing? Spark Plugs?

415

336 and 340/341 are crankshaft position and camshaft position sensors circuit issues, respectively. 420 could be an exhaust leak, causing the Cat sensors to misread, or just an issue caused by the other codes. The 31 code is kind of confusing, it is either an ABS issue, or if it is supposed to read 301 it is a misfire in cylinder #1. You may try to contact a dealer and see if the vehicle ever had any recalls performed, and if there are any updated reprograms for the ECM. From the sounds of it, though, there may be a computer issue for it to be throwing all of these codes at the same time. I would recommend checking your wires for loose connections, rub-throughs, corrosion, etc. Especially if you have not had any work performed recently.

10

timing belt

1 of 1 people found this helpful.
4,280

Hmmm.... Does it restart and run normally? If not, sure: I'd indeed check the t-belt, as noted above. Note that misfire codes are PO301-4. The crank/cam shaft sensor codes hint toward the t-belt, rather than wiring issues. The PO420 is just your cat getting old, bad gas, or the electrical fairies that plague Subies and Toyotas with this code. BTW, I would NOT ignore the knock sensor, as they're cheap (same as Nissan), and will contribute to smoother running, engine protection, and improved power and fuel eco. Good luck.

Your Answer

Add photo

Related Questions

Legacy

Looking for a Used Legacy in your area?

CarGurus has 15,855 nationwide Legacy listings starting at $999.

ZIP:

Search Subaru Legacy Questions

Subaru Legacy Experts

#1 Anthony_60
Anthony_60
Reputation 1,240
#2 Nick Eidemiller
Nick Eidemiller
Reputation 700
#3 dandyoun
dandyoun
Reputation 680
View All

Related Models For Sale

Used Subaru Impreza
187 Great Deals out of 17,838 listings starting at $1,250
Used Subaru Outback
345 Great Deals out of 38,530 listings starting at $1,995
Used Subaru Forester
356 Great Deals out of 29,331 listings starting at $1,750
Used Honda Accord
812 Great Deals out of 84,287 listings starting at $1,050
Used Toyota Camry
998 Great Deals out of 90,917 listings starting at $650
Used Honda Civic
654 Great Deals out of 88,603 listings starting at $995
Used Nissan Altima
1,027 Great Deals out of 81,564 listings starting at $1,200
Used Toyota Corolla
786 Great Deals out of 73,830 listings starting at $1,995
Used BMW 3 Series
971 Great Deals out of 31,729 listings starting at $1,000
Used Acura TL
233 Great Deals out of 6,297 listings starting at $999
Used Audi A4
227 Great Deals out of 10,877 listings starting at $1,899

Used Cars For Sale

2017 Subaru Legacy For Sale
8 Great Deals out of 10,161 listings starting at $17,432
2016 Subaru Legacy For Sale
29 Great Deals out of 836 listings starting at $10,995
2015 Subaru Legacy For Sale
42 Great Deals out of 1,024 listings starting at $10,700
2014 Subaru Legacy For Sale
42 Great Deals out of 1,105 listings starting at $8,999

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.