OBDII codes, Multiple; PO130, PO1133, PO136, runs good

[divingfe]

Now, I'm confused. 2002 Forester, Automatic, basically in VERY good condition, only 75K easy miles.  A few weeks ago, got intermittent, resettable, PO130 codes which would repeat after about 30-50 miles (all reset normally).  Also noticed a gradual increase in exhaust noise, so, I figured a leak.. no biggie to fix.  Comes time for MA inspection; investigated leak beforehand, and found the gasket between the rear cat and long pipe back to the muffler was leaking.  Got it fixed.   BTW the car runs great; smooth, just hums like a top, before after, and during this tale (except for the exhaust leak itself, of course). Immediately after picking up the repaired car, the light was on, but this time, an PO1133 code!!!.  Looked it up; also exhaust related, - front sensor/connections??--- but it came on immediately(1 minute) after being reset, instead of the 'advertised' two driving cycles. Check out this code and reset it a few times.  Took the car back to shop, they replaced the front O2 sensor.  NO light until about 20 miles.   Oh well, So, I checked it out & reset a code PO136!!!   No more 1133 code!!  I went about 50 miles total, with a couple of resets. Took it back and now it's in the shop, today, hopefully, I'll hear something soon.  He may change the rear sensor for troubleshooting- if the light comes back, then it is DEFINITELY a wiring issue- which I kind of suspect anyway, due to the fact of three different codes (really two new ones, because of the actual exhaust leak initially).

Weather permitting (HAHAHA), I'd troubleshoot the wiring per ALLDATA instructions, but how do I get to the B136/B134 connectors, etc.?? Are they up under the dashboard to the right of center, and what panels need removing to get to them??? I have a picture of the wiring harness, but the detail doesn't let me see what/where to go to get at the connectors, and I don't want to 'blow' an airbag in the process.

Also, any clues as to the multiple lights?? or fixes???  Thanx for your ideas

[Fairtax4me]

P0130 is one front sensor.

P0136 is the other front sensor.

 

1133 is a heater malfunction which would usually indicate a bad sensor.

 

None of these have to be messed with to change that exhaust gasket, but if that gasket went bad it sounds like you have some rust issues, which could also mean corrosion of the sensors.

 

Odd to have both bite the dust at the same time for sure, but none of those codes really scream wire problem to me.

 

B134/136 are the ECU connector and should be under a panel under the passenger carpet.