P0137, two part question

[MooF]

P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
Anyone ever get this code?
And did you resolve it by replacing the O2 sensor or any other resolution?

Here is more info on it:
http://www.obd-codes.com/p0137

Conditions this occurred:
I was driving around for a good 2 hours in the city when this occurred, and I wasn't surprised to see a CEL during this time (just had a hunch, don't know why, the car wasn't behaving differently at all). It was about -15C that night and the car probably had about enough.
The only other thing I can think of is that my oem resonator has a small amount of rust beginning to form near the original weld joints. Maybe there is a slight exhaust leak near the rear O2 sensor..? I actually have a Magnaflow replacement resonator, long story, but essentially I thought my exhaust was too loud when I first put my Magnaflow muffler on, so I went back to the original reso. (turns out I got accustomed to the sound and regret not keeping the new reso on). I still have it and will consider putting it back on.
Summary, my hunch is that all the city driving I was doing triggered this CEL at some point... Any other thoughts?

Part II.
I purchased an OBDII code reader to reset the code. After doing so, the SAAB wouldn't turn over. All the electrical components came on but trying to crank the car only produced a "click".
I left the car for 20 mins and prayed I didn't mess something up by resetting the code, and came back and the car started.

Has this happened to anyone? why it didn't start after a code reset?
Maybe having the ignition ON, (lights on for a couple minutes) while doing the code reset caused the battery to weaken. (but then i would expect to at least achieve a weak crank?
I'm going to test the battery voltage now and find out if my batt's on the way out?

Cheers everyone!

[MooF]

Part II addendum:
Tested the battery, only 35% in the morning. I tried turning on the charger, but after reaching 41% the charger went into battery desulfation mode, which would take 10 hrs, which I didn't want to wait for.
So I started the car, let it run a bit, and then the battery read 55%, but dropped rapidly.

I tested my wife's 3 year old Nissan battery and it was 90% in the cold morning.

Do my numbers suggest early battery replacement?

[ctrlz]

Originally Posted by MooF

Do my numbers suggest early battery replacement?

Is this the original battery?
My battery would only charge to 75% after 4 years. Battery replacement for a 2003 is a no-brainer at this point.

[MooF]

Originally Posted by ctrlz

Is this the original battery?
My battery would only charge to 75% after 4 years. Battery replacement for a 2003 is a no-brainer at this point.

I'm not the original owner. One of the mechanics told me its original, but apparently he wouldn't be the first mechanic to be wrong
I agree, its a no-brainer either way since it's showing very subtle signs of weakness..I hate the thought of even asking for a boost, let alone being stranded somewhere.
I'm getting quotes tomorrow but will likely end up at the dealer for replacement so I can do a couple other minor things at the same time.

Cheers.

[JonV]

I'd recommend getting a battery at a place other than a deal.....that battery will be an Interstate...not a bad battery but the dealer sells it high. Size is group 48, it will have the proper CCA's etc...look at warranty, replacement/pro-rating etc when you go to buy. Go to a place with High inventory turnover.

[MooF]

Part Source has Group48, $109 (cdn). Didnt ask the brand.

I think the dealer wants ~ $150 installed. Have to call to find out tomorrow.
But I can do it myself, plus save the trip down.

edit add: I've kinda gotten off track, but I guess we're saying I should
replace the battery?

[ctrlz]

P0137

Low voltage on rear O2 sensor. Sensor must read low voltage for at least 30 sec to set a CEL.

WIS says you should check connections first. If voltage present at harness and connections look good, then replace sensor.

The connectors for both O2 sensors are at the right rear of the engine as you face front of car. Below the coolant overflow tank. Each connector is a sliding latch type, with 4 wires coming out the top. The connector for the rear sensor is on the left as you face the engine. This is what the WIS shows. I can check my car later if this isn't as obvious as it sounds.

I would replace battery before replacing the sensor. Your battery voltage may have something to do with the CEL. Based on your reports, your battery is in pretty sad shape. I would not want to troubleshoot electrical problems knowing the battery is bad.

[MooF]

Thanks for the reply.
I'm going to replace the battery while its still starting and not take any chances. I pay now or later..

[MooF]

Originally Posted by JonV

I'd recommend getting a battery at a place other than a deal.....that battery will be an Interstate...not a bad battery but the dealer sells it high. Size is group 48, it will have the proper CCA's etc...look at warranty, replacement/pro-rating etc when you go to buy. Go to a place with High inventory turnover.

dealer wants $197, before tax, not installed.
Are they nuts? Will GM make up their billions of bankruptcy by ripping us off? I know these are rhetorical questions, but I'm fuming just because.

[AKS]

$197 for an battery? That's insane.....

Which dealership if you dont mind me asking?

[MooF]

Royfoss (formerly Midtown) Saab Saturn

[jlrdrony]

Originally Posted by AKS

$197 for an battery? That's insane.....

Which dealership if you dont mind me asking?

I have got a GM battery, in the year 2003, for the opel omega and still is working and good functionality.
the GM batteries have a warranty for three years.
the price was 133.52 € VAT not included (in the year 2003).

you must evaluate if worthwhile.

[AKS]

good look, I will keep that in mind.

I don't think I've spent more then $100 cdn for a battary on my previous cars.

On my c230 coupe the battery was only $100 cdn which I purchased at a local mb dealer.

[MooF]

So my indy shop "OK Tire" uses BatteryDirect.com 'Platinum' batteries and label them with OK Tire Battery.
Price is in between Part Source & the dealer @ $150 installed.

But here's the best part, 5 year free replacement (not pro rated) from the day of purchase. BatteryDirect has an 800 number and if your battery fails anywhere within Canada they will send you to the nearest OK Tire or send a courier out to you with a replacement free of charge.

oh, the battery is just about toast, had some trouble starting after leaving the radio on for 25 mins. So not taking any more chances, final answer.