2000 Camaro - P0137 O2 Sensor Circuit Low Voltage (Bank1,S2)

Y2KCamaro · **Joined:** Sat Sep 13, 2008 1:39 pm **Posts:** 7

I have a 2000 Camaro V6 3.8L and it originally had the trouble code: P0420 Catalyst System Efficiency Below Threshold (Bank 1)

So I got the catalytic converter replaced at a Magnaflow dealer the other day with a universal converter. I noticed that the converter they installed was a little smaller than the original OEM converter.

The Camaro actually feels like it has more flow and sound a little louder (has a flowmaster muffler). When I saw them welding the converter, the 2nd oxygen sensor was awfully close to where the weld will be made but didn't think much of it. I saw them install the converter and didn't see any flames going towards the oxygen sensor.

I inspected the old factory converter and it was extremely plugged inside with all it's elements melted inside. I drove the car home from the shop and cleared the P0420 by disconnecting the battery.

Two days later, the SES light came on again but this time it was P0137 Oxygen Sensor Circuit Low Voltage (Bank 1, Sensor 2).

What I suspect is that the 2nd 02 sensor got damaged in the process of the weld or they installed (by accident) the wrong converter to my Camaro (not up to specs). What do you suggest? Thanks!

Sponsored Links · **Joined:** 29 Jun 2004 08:12 pm **Posts:** N/A

jeff compton · **Posted:** Mon Sep 15, 2008 8:21 am

Sounds quite likely!

FergusonTO35 · **Joined:** Mon Sep 08, 2008 9:35 pm **Posts:** 154

My money is on a cooked O2 sensor. Plugged catalysts can glow cherry red, which can ruin an O2 just the same.

Y2KCamaro · **Joined:** Sat Sep 13, 2008 1:39 pm **Posts:** 7

But what a coincidence that it gave out a code for the 2nd O2 sensor as soon as I got the catalytic converter replaced. I feared that the O2 sensor was damaged or the wrong cat was installed...

Now this week the SES code is no longer on anymore...eh?

Mohawkmtrs · **Posted:** Tue Sep 16, 2008 6:27 am

Are you saying the code is no longer stored or the MIL is no longer lit?

Y2KCamaro · **Joined:** Sat Sep 13, 2008 1:39 pm **Posts:** 7

Well since I got the Cat converter replaced last Thursday evening, the SES light came turned on on Saturday afternoon (turned off on sunday) and it turned on again yesterday (Monday) afternoon and is still back on as we speak. I do a mix of city and freeway driving.

Could it be possible that the 2nd oxygen sensor is not liking the new reading from the new cat converter? And if so, how can i confirm that? Thanks!

jeff compton · **Posted:** Tue Sep 16, 2008 8:54 am

could be damaged from removal or welding, poor grounding, damaged connector blown fuse etc, etc! I'd doubt the brand new converter was causing the 02 code until the 02 was verified as okay!

Y2KCamaro · **Joined:** Sat Sep 13, 2008 1:39 pm **Posts:** 7

...and you don't think they put the wrong cat by accident? Now the SES has been on since it came back on...It drives just fine, even better with the new cat but I know the SES code is more emissions than performance. What do you suggest I do? Have the O2 checked, and if so, how is that done? Thanks for all your help so far!

Y2KCamaro

FergusonTO35 · **Joined:** Mon Sep 08, 2008 9:35 pm **Posts:** 154

The best way to check the O2 sensor and catalyst would be to examine the data stream for the bank one sensors with a scan tool. Usually if the converter is faulty it will also throw a P0420. At this point I would recommend you take it back to the place that installed your new converter and explain to them that this problem started after they installed a new catalyst. I think the O2 sensor was damaged, either by the old catalyst overheating or from the installation of the new one.

2000 Camaro - P0137 O2 Sensor Circuit Low Voltage (Bank1,S2)

Who is online