Check Engine O2 Sensor Issue

[Turk]

Howdy,

I took a trip to Colorado and put on 3200 miles in about a week, went 4 wheelin' etc.,

the trip went flawlessly on my all-around Amsoil'd up 03 GMC Sierra with 110k on it.

I got gas at a older Conoco station on south central Colorado and a ways after that, the check engine light came on. Checked the manual and it said it could be the gas cap being loose or asked if there was a recent fill of gas.

It came off after another tank or so of gas, so I figured it was the gas !!

So, the light came on yesterday after a few tanks of gas.

Had a shop check the code and he said Sensor 1, Bank 1 O2 Sensor.

Said it could be the bad gas still causing it (??)!

Could that be true? It idles kinda rough now.

This is after I put in Amoco 92 Octane Non-Oxy gas a couple days ago.

I just put in 1.5 bottles of new Amsoil PI in the gas - will that help??

Do you think I need to change the Oxygen Sensor?? Where is that one??

Thanks for assistance on this...

 

[Turk]

Anyone??

 

[Merkava_4]

It would had been nice to have the code posted, but I'll work around that.

The computer will throw a code if it determines that the sensor data it's receiving is out of an excepted range OR it receives no data at all from the sensor.

The computer will send a 5 volt reference signal to the sensor. The sensor then sends a voltage signal back to the computer after it (the sensor) measures the parameter it's assigned to measure.

After the technician reads the code, he will then first verify that the sensor is receiving its 5 volt reference signal. If it's been determined that the sensor is in fact receiving the 5 volt reference signal, he will then back probe the sensor to verify that it's sending its own voltage signal BACK to the computer. This is done so that the technician can verify continuity between the sensor and the computer AND to check the range of the output signal ( also known as the return signal) back to the computer.

The signal going back to the computer will always very in voltage depending on the parameter being measured. In this case being the oxygen sensor circuit, it would be the oxygen content of the exhaust. There's an extreme + or - voltage values that the oxygen sensor will send. If the voltage values being sent back to the computer are outside the normal excepted limits, the computer will throw the code. The computer knows ahead of time what the maximum + or - values should be.



flatlandtacoma, I suppose this is another one of my troll posts, right?

 

[alanu]

I'm having a brain ____ right now but I recall the reference voltage on many cars to be 450mv NOT 5V.

do a cross count test with a scope. You should get at least 10 to 12+ cross counts in 10 seconds. Hopefully the sweep should be within .1v - .8ish volts.

On many occasions the code read will correlate with the problem your having. Theres usually an OBDII code that will determine a signal issue or a heater element issue. From the sounds of it the "confuser/computer" is detecting issues with lack of crosscounts or out of range amplitude.

 

[Merkava_4]

You're right, it is 450 mV. A lot of the other sensors i.e. Manifold Absolute Pressure Sensor will have a 5V reference.

From AllData:

Quote:

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P0130
CIRCUIT DESCRIPTION
Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the vehicle is first started, the powertrain control module (PCM) operates in an Open Loop mode, ignoring the HO2S signal voltage when calculating the air-to-fuel ratio. The PCM supplies the HO2S with a reference, or bias, voltage of about 450 mV. The HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage once in Closed Loop. A high HO2S voltage output indicates a rich fuel mixture. A low HO2S voltage output indicates a lean mixture. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature, and to provide an accurate voltage signal. If the PCM detects an active HO2S 1 signal of a lower than calibrated minimum amplitude, DTC P0130 will set.

---

Quote:

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P0107
CIRCUIT DESCRIPTION
The manifold absolute pressure (MAP) sensor responds to changes in intake manifold pressure which gives an indication of the engine load. The MAP sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit and provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP Sensor signal circuit which is relative to the pressure changes in the manifold. With low MAP such as during idle or deceleration, the PCM should detect a low MAP sensor signal voltage. With high MAP such as ignition ON, engine OFF or wide open throttle (WOT), the PCM should detect a high MAP sensor signal voltage. This MAP sensor will indicate pressure between 10-104 kPa . The MAP sensor is also used in order to calculate the barometric pressure (BARO) when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range. If the PCM detects a MAP sensor signal voltage that is excessively low, DTC P0107 sets.

---

 

[Turk]

Thanks Guys, but what do you think?

He did not say the code, but mentioned it was exhaust.

Could it have been/still is bad Gas that caused Sensor 1, Bank 1 to trip?? Does Sensor 1, Bank 1 tell you anything??

Would it need to be replaced or could the Amsoil P.I. help?

Anything else??

Thanks...

 

[wantin150]

Sensor 1, Bank 1 tells you the location of the O2 sensor. Your vehicle (like mine) may be equipped with 2 O2 sensors, one pre-cat and the other after-cat. I've had both of mine go and each time it was a "heater circuit malfunction".

The code would help as it could narrow the scope of the diagnostic.

 

[wiswind]

There are a number of codes with regard to the oxygen sensors.
Bank 1, Sensor 1 is the cylinder bank that contains cylinder #1, the sensor that is before the catalytic converter.

My vehicle has 2 catalytic converters......so I have 4 oxygen sensors.....2 "upstream" 1 before each catalytic converter...that are used by the computer to determine fuel trim. Then there are 2 "downstream", 1 after each catalytic converter that only serve to monitor the catalytic converters to make sure that they are working (catalyst efficiency).

When you get the code(s) read, you normally have to ask them for the specific code.
The thing that you want to know is if the OBDII system is seeing a problem with the SENSOR, or if the sensor is working correctly...and is reporting a problem.

Examples of sensor problems would be codes that report a problem with the heater circuit (could be the wiring, and not the sensor) or switching too slow, or out of range, etc.

Examples of the sensor working correctly and reporting a problem would be Lean or Rich codes.

If the Check Engine light is still lit.....it would be worthwhile to get the code(s) read again to get the specific code.

 

[mechtech2]

O2 sensors usually produce voltage, but some newer ones work by resistance.
AT 110k, your sensor is due for a replacement.
Sure, many work fine at that mileage, but many are slow and sluggish to respond, or are out of range.
Replace the one nearest the cylinder head. The one after the cat is to determine that the cat is working.

 

[Turk]

The interesting thing on this is that an O2 Sensor went out a couple months ago. When that one went out, the Engine Light "Blinked" for a long time.

When this one went, it is on "Steady".

Hummm...(?)

 

[wiswind]

At least on my vehicle, a blinking Check Engine Light is supposed to mean that it is a problem that can cause damage to the catalytic converter.
A misfire code will cause a blinking CEL while it is happening, then the CEL will stay on solid until the set number of "drive cycles" has taken place.

I would want to know specifically what the code was.
You can then look up the code and see what the specific information is.
An example, I had code read once.....the person said "misfire".....I was looking over his shoulder and read the code P0304, which is a misfire on cylinder #4, more information.

As mechtech2 mentioned, oxygen sensors slow down as they get older.....some sooner than others.
The OBDII system will monitor to make sure that it is "within specifications" and will set a code and light the CEL if you get outside the "window".
It should not cost a bunch to get a sensor and put it in, if you wish to change it.

 

[Turk]

Thanks. The one I had put in costed a few Hundres Dollars !!

What the ----

 

[wiswind]

WOW!....mine are under $60 for Motorcraft brand, I guess that prices can vary.

 

[Turk]

Yea, I asked them and they said it was an expensive one.

I think a person can but a code reader. I wonder if one comes with a Hypertech Power Programmer ??

 

[Turk]

Ok, I got the code.....

It' s Code P0131. O2 sensor Low Voltage Sensor 1, Bank 1.

Which side is it on, Driver's or Passenger's ??

Something I can do with P-Oil & a wrench or should I bring it in ??

Thanks...

 

[wiswind]

Bank 1 normally is the bank of cylinders that has Cylinder #1.
Sensor #1 is normally the "upstream" sensor.....the one before the catalytic converter.

If you only have 1 catalyitc converter, you likely only have 2 oxygen sensors.....1 before, and 1 after the converter.

Penetrating oil is good for helping with the threads...but be very careful in application......make sure that you get it ONLY on the threads.
You don't want to get it onto the upper part of the body of the sensor....or where the wires enter the sensor body.
Reason, most oxygen sensors work by producing a voltage.....that is created by a chemical reaction....that is proportional to the oxygen content of the air on the inside part (in the exhaust), and the outside atmosphere.
So you don't want to seal up the outside exposure by getting the oil over the outer sensor body (and into the inner workings).

 

[Turk]

Do you know or how do I find out which side it's on ??

 

[wiswind]

I don't know for your particular vehicle.

 

[Turk]

I got 'er replaced!