Dark times but I see a light.... '06 Vibe AWD, 160k

[eastcoastvibe]

Been some challenging financial times and have tried to stay current with the upkeep of my Vibe. The upkeep, unfortunately, had outpaced the finances up until very recently. I'm in a decent place now and need to either pour some, I'm thinking, major work into the Vibe or seek out another set of wheels. Aside from the gas mileage being terrible, the car actually runs fine. I'm due for an inspection in the next few weeks and am thinking that I may face some probs with the engine light on and so forth.

I recently went out and bought an Autel MS310 OBDII scanner. After the scan, I see that there are several codes that are flagged. I'm not afraid to get in and work on this vehicle but if it is going to take major equipment, I may not be prepared for that.

The codes flagged are as follows:

P0171 - System too lean bank 1
P0031 - HO2S heater control circuit low bank 1 sensor 1
P0037 - Same as above but sensor 2
P0134 - O2 sensor circuit No activity detected bank 1 sensor 1

Then, I also received the following two codes included just after the above four codes but they happened to be duplicates of the same codes above but with "Pd" noted on the scanner screen:

P0031 - same as above but with "Pd"
P0037 - same as above but with "Pd"

Any advice is so greatly appreciated. If possible, please don't be afraid to be overly specific as I am a newbie at this for the most part

[gtv237]

Sounds like your precat O2 sensor is shot. If your scanner can view live data, find the O2 voltage and see if its consistent. It should change rather dramatically when you press the gas. If it stays at the same number or just at zero then there is definitely an issue.

I would start by making sure both O2 sensors are plugged in. I've seen people struggle with O2 issues just to find out they were unplugged or not clicked in all the way. Next I would check the wiring to the sensors. Make sure none of the wires melted or rubbed against anything. Also disconnect the connector and make sure the pins are not corroded.

If everything looks alright I would replace the precat sensor.

[Derf]

Sounds like your precat O2 sensor is shot. I would start by making sure both O2 sensors are plugged in.

2nd that, check the pre cat sensor, and wiring harness occasionally they do go out.

[vibrologist]

The P0171 system lean, bank 1 (the only bank we have) is often caused by a vacuum leak after the MAF sensor. This vacuum leak reduces the amount of air flowing through the MAF sensor and that sensor's data is used to calculate the amount of fuel.

If the amount of fuel is always too little then the HO2 sensor will not invert. That could explain why no activity was detected.

So I would not immediately declare the HO2 sensors dead. There is also a method to bench test a O2 sensor.

http://www.youtube.com/watch?v=YL6xkOZxHZ0" onclick="window.open(this.href);return false;

[gtv237]

The P0171 system lean, bank 1 (the only bank we have) is often caused by a vacuum leak after the MAF sensor. This vacuum leak reduces the amount of air flowing through the MAF sensor and that sensor's data is used to calculate the amount of fuel.

If the amount of fuel is always too little then the HO2 sensor will not invert. That could explain why no activity was detected.

So I would not immediately declare the HO2 sensors dead. There is also a method to bench test a O2 sensor.

http://www.youtube.com/watch?v=YL6xkOZxHZ0" onclick="window.open(this.href);return false;

But if you look at the big picture, there's also a heater circuit malfunction in sensor 1. A vacuum leak wouldn't cause that so the first suspect is the sensor itself. I would also measure the temperature before and after the cat to make sure it's not plugging up and overheating sensor 1.

[vibrologist]

The P0171 system lean, bank 1 (the only bank we have) is often caused by a vacuum leak after the MAF sensor. This vacuum leak reduces the amount of air flowing through the MAF sensor and that sensor's data is used to calculate the amount of fuel.

If the amount of fuel is always too little then the HO2 sensor will not invert. That could explain why no activity was detected.

So I would not immediately declare the HO2 sensors dead. There is also a method to bench test a O2 sensor.

http://www.youtube.com/watch?v=YL6xkOZxHZ0" onclick="window.open(this.href);return false;

But if you look at the big picture, there's also a heater circuit malfunction in sensor 1. A vacuum leak wouldn't cause that so the first suspect is the sensor itself. I would also measure the temperature before and after the cat to make sure it's not plugging up and overheating sensor 1.

I agree, gtv, I don't argue. I added pointers so eastcoast has a better chance to get it going on the cheap.

Probing the temperature before and after the catalytic converter is a great idea.

[eastcoastvibe]

Sounds like your precat O2 sensor is shot. If your scanner can view live data, find the O2 voltage and see if its consistent. It should change rather dramatically when you press the gas. If it stays at the same number or just at zero then there is definitely an issue.

I would start by making sure both O2 sensors are plugged in. I've seen people struggle with O2 issues just to find out they were unplugged or not clicked in all the way. Next I would check the wiring to the sensors. Make sure none of the wires melted or rubbed against anything. Also disconnect the connector and make sure the pins are not corroded.

If everything looks alright I would replace the precat sensor.

I do hope all that weigh in here are patient with me and the following questions as I am very new to this but want to dig in, if it is worth it. Where might I find the precat O2 sensor on my vehicle? I do know the scanner can operate and provide readings while the engine is running so I will check to see if I can get a read on the O2 voltage when I press the gas as suggested. There is mention of more than one sensor. Same question. Where are the other sensor(s)? Last couple of questions before I head off to dreamland. If the precat O2 sensor is bad, where can I find the part# for the sensor and where might be the best place to purchase a new one? Any calibration necessary or special tools needed to install?

Many thanks!

[vibrologist]

ecv: bookmark this:
http://www.samarins.com/diagnose/codes.html" onclick="window.open(this.href);return false;

This is also helpful because it shows diagrams of various systems.
http://www.gmpartsonline.net/2006-pontiac-vibe.html" onclick="window.open(this.href);return false;


And this thread shows pictures of the 2 oxygen sensors on the car, one before and one after the catalytic converter. You need a special socket that has a slot for the wires to remove the sensor. Use anti-seize compound on the threads when you put in a sensor. Those sensor locations would be great for taking temperature.

viewtopic.php?t=32802" onclick="window.open(this.href);return false;

Any parts store will have the special tool and the sensors. No calibration required. RockAuto.com can be a less expensive source. I would stay away from universal sensors because they require you to splice the wires.

[gtv237]

Here is a visual on the precat o2 sensor (Bank 1, Sensor 1). The photo is taken behind the engine from the top.