Need Help With Cel Please
Senior Member
Joined: Jul 2004
Posts: 5,155
Likes: 0
From: Eau Claire, WI
Vehicle: 97 Tib
The IAT wouldn't cause the o2 sensors to malfunction though^
And Redz, he has a header^
Quote from The Grandaddy..
DTC - P0131 (OXYGEN SENSOR CIRCUIT LOW VOLTAGE)
PRIMARY SENSOR: Front Oxygen Sensor
SECONDARY SENSOR(S): None
SYSTEM(S): Bosch
NORMAL PARAMETERS: Sensor output using scan tool with engine at normal operating temperature:
200 millivolts or less when decelerating suddenly from 4000 RPM
600-1000 millivolts when engine is suddenly raced.
Sensor heater resistance: 3-5 ohms at 194?F (90?C) ECT
CIRCUIT DESCRIPTION
The Engine Control Module (ECM) uses oxygen sensor signals to maintain the air fuel mixture at the ratio resulting in optimum fuel economy and reduced emissions. The oxygen sensor measures the amount of oxygen in the exhaust gases. The oxygen sensor is coated with a catalyst metal that causes the sensor to produce a voltage in the millivolt (mV) range whenever the sensor reaches a temperature of at least 600?F (315?C) and it is exposed to oxygen. The amount of oxygen in the exhaust gases indicates, to the front oxygen sensor, whether the air fuel mixture being supplied to the engine cylinders is rich or lean. The readings of the rear oxygen sensor are used to indicate the efficiency of the catalytic converter. The ECM calculates catalytic converter efficiency by comparing the rear oxygen sensor signal to the front oxygen sensor signal.
A normal oxygen sensor signal will constantly fluctuate above and below 500 mV, with the front oxygen sensor signal frequency of at least 5Hz (one crossing from above 500Mv to below 500Mv or below 500Mv to above 500Mv every 100ms) at 2500 RPM. Due to the effect of the catalytic converter, the rear oxygen sensor signal frequency will be lower than the front oxygen sensor signal frequency. When the front oxygen sensor output signal is above 500 mV, the air fuel mixture is considered to be rich; if the signal falls below 500 mV, the mixture is considered to be lean. If the rear oxygen sensor signal coincides with the front oxygen sensor signal a large percentage of the time, this indicates a loss in efficiency of the catalytic converter or a malfunction within the fuel system.
An oxygen sensor is inaccurate when the temperature falls below 600?F (315?C). The oxygen sensor uses a heating element to shorten sensor warm up time (open loop operation) and help keep sensor temperature above 600?F (315?C).
FAILURE CONDITIONS
After the Front Oxygen Sensor Heater is on for 3 minutes and 20 seconds, the ECM continuously measures the front oxygen sensor's output in 0.5 second intervals. If during two back-to-back trips the front oxygen sensor's output falls below -128 millivolts for 0.5 seconds, the ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on. This code indicates an unusually lean fuel air mixture being read by the front oxygen sensor or ECM.
Translation... You've got an air leak, or you're running damn lean.
P0134 Oxygen Sensor Circuit Inactive (Bank1, Sensor2)
DESCRIPTION
Obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three way catalytic converter is used, but for the most efficient use of the three-way catalytic inverter, the air ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio. The oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity of the stoichiometric air-fuel ratio. This characteristic is used to detect the oxygen concentration in the exhaust gas and provide feedback to the computer for control of the air-fuel ratio. When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen sensor informs the ECM of the LEAN condition (small electromotive force: 0V)
When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio the oxygen concentration in the exhaust has is reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive force: 1V). The ECM judges by the electromotive force from the oxygen sensor whether the air-fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor causes output of abnormal electromotive force, the ECM is unable to perform accurate air-fuel ratio control. The heated oxygen sensors include a heater which heats the Zirconia element. The heater is controlled by the ECM. When the intake air volume is low (the temperature of the exhaust gas is low) current flows to the heater to heat the sensor for accurate oxygen concentration detection.
DTC detection condition
Background
When the heated oxygen sensor begins to deteriorate, the oxygen sensor signal response becomes poor.
The engine control module forcibly varies the air/fuel mixture to make it leaner and richer, and check the response speed of the heated oxygen sensor. In addition, the engine control module also checks for an open circuit in the heated oxygen sensor output line.
Check area
Coolant temperature sensor: Normal.
Heated oxygen sensor signal voltage has continued to be 0.1V or lower for 3 min. or more after the starting sequence was completed.
Engine coolant temperature is higher than 80?C (176?F).
Engine speed is higher than 1,200 r/min.
Engine load is 25% or more.
Judgment Criteria
Input voltage supplied to the engine control module interface circuit is 4.5V or more when 5V is applied to the heated oxygen sensor output line via a resistor.
Check area
Coolant temperature sensor: Normal.
Engine coolant temperature sensor is 50?C (122?F) or more.
Engine speed is between 1,500 and 3,000 r/min < M/T > or 1,100 and 3,000 r/min < A/T >.
Engine load is 25 - 60%.
Intake air temperature is -10?C (14?F) or more.
Under the closed loop air-fuel control.
Monitoring Time: 8 sec
Judgment Criteria
When the air-fuel ratio is forcibly changed (lean to rich and rich to lean), the heated oxygen sensor signal doesn't provide response within 1.28 sec.
Monitored only once per trip.
Probable cause
Heated oxygen sensor deteriorated
Open circuit in heated oxygen sensor output line
Engine control module failed
Both have something to do with running lean, or the o2 sensor running so cold, that it reads lean (even if you're not).
I would check the O2 sensor wiring for the proper 5V feed for the heating element. If you're not getting 5V then you'll have to go back and check the wiring to figure out where the fault is.
If you DO have 5V, then the problem is it's reading lean. You need to figure out WHY it's reading lean.
And Redz, he has a header^
Quote from The Grandaddy..
DTC - P0131 (OXYGEN SENSOR CIRCUIT LOW VOLTAGE)
PRIMARY SENSOR: Front Oxygen Sensor
SECONDARY SENSOR(S): None
SYSTEM(S): Bosch
NORMAL PARAMETERS: Sensor output using scan tool with engine at normal operating temperature:
200 millivolts or less when decelerating suddenly from 4000 RPM
600-1000 millivolts when engine is suddenly raced.
Sensor heater resistance: 3-5 ohms at 194?F (90?C) ECT
CIRCUIT DESCRIPTION
The Engine Control Module (ECM) uses oxygen sensor signals to maintain the air fuel mixture at the ratio resulting in optimum fuel economy and reduced emissions. The oxygen sensor measures the amount of oxygen in the exhaust gases. The oxygen sensor is coated with a catalyst metal that causes the sensor to produce a voltage in the millivolt (mV) range whenever the sensor reaches a temperature of at least 600?F (315?C) and it is exposed to oxygen. The amount of oxygen in the exhaust gases indicates, to the front oxygen sensor, whether the air fuel mixture being supplied to the engine cylinders is rich or lean. The readings of the rear oxygen sensor are used to indicate the efficiency of the catalytic converter. The ECM calculates catalytic converter efficiency by comparing the rear oxygen sensor signal to the front oxygen sensor signal.
A normal oxygen sensor signal will constantly fluctuate above and below 500 mV, with the front oxygen sensor signal frequency of at least 5Hz (one crossing from above 500Mv to below 500Mv or below 500Mv to above 500Mv every 100ms) at 2500 RPM. Due to the effect of the catalytic converter, the rear oxygen sensor signal frequency will be lower than the front oxygen sensor signal frequency. When the front oxygen sensor output signal is above 500 mV, the air fuel mixture is considered to be rich; if the signal falls below 500 mV, the mixture is considered to be lean. If the rear oxygen sensor signal coincides with the front oxygen sensor signal a large percentage of the time, this indicates a loss in efficiency of the catalytic converter or a malfunction within the fuel system.
An oxygen sensor is inaccurate when the temperature falls below 600?F (315?C). The oxygen sensor uses a heating element to shorten sensor warm up time (open loop operation) and help keep sensor temperature above 600?F (315?C).
FAILURE CONDITIONS
After the Front Oxygen Sensor Heater is on for 3 minutes and 20 seconds, the ECM continuously measures the front oxygen sensor's output in 0.5 second intervals. If during two back-to-back trips the front oxygen sensor's output falls below -128 millivolts for 0.5 seconds, the ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on. This code indicates an unusually lean fuel air mixture being read by the front oxygen sensor or ECM.
Translation... You've got an air leak, or you're running damn lean.
P0134 Oxygen Sensor Circuit Inactive (Bank1, Sensor2)
DESCRIPTION
Obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three way catalytic converter is used, but for the most efficient use of the three-way catalytic inverter, the air ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio. The oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity of the stoichiometric air-fuel ratio. This characteristic is used to detect the oxygen concentration in the exhaust gas and provide feedback to the computer for control of the air-fuel ratio. When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen sensor informs the ECM of the LEAN condition (small electromotive force: 0V)
When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio the oxygen concentration in the exhaust has is reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive force: 1V). The ECM judges by the electromotive force from the oxygen sensor whether the air-fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor causes output of abnormal electromotive force, the ECM is unable to perform accurate air-fuel ratio control. The heated oxygen sensors include a heater which heats the Zirconia element. The heater is controlled by the ECM. When the intake air volume is low (the temperature of the exhaust gas is low) current flows to the heater to heat the sensor for accurate oxygen concentration detection.
DTC detection condition
Background
When the heated oxygen sensor begins to deteriorate, the oxygen sensor signal response becomes poor.
The engine control module forcibly varies the air/fuel mixture to make it leaner and richer, and check the response speed of the heated oxygen sensor. In addition, the engine control module also checks for an open circuit in the heated oxygen sensor output line.
Check area
Coolant temperature sensor: Normal.
Heated oxygen sensor signal voltage has continued to be 0.1V or lower for 3 min. or more after the starting sequence was completed.
Engine coolant temperature is higher than 80?C (176?F).
Engine speed is higher than 1,200 r/min.
Engine load is 25% or more.
Judgment Criteria
Input voltage supplied to the engine control module interface circuit is 4.5V or more when 5V is applied to the heated oxygen sensor output line via a resistor.
Check area
Coolant temperature sensor: Normal.
Engine coolant temperature sensor is 50?C (122?F) or more.
Engine speed is between 1,500 and 3,000 r/min < M/T > or 1,100 and 3,000 r/min < A/T >.
Engine load is 25 - 60%.
Intake air temperature is -10?C (14?F) or more.
Under the closed loop air-fuel control.
Monitoring Time: 8 sec
Judgment Criteria
When the air-fuel ratio is forcibly changed (lean to rich and rich to lean), the heated oxygen sensor signal doesn't provide response within 1.28 sec.
Monitored only once per trip.
Probable cause
Heated oxygen sensor deteriorated
Open circuit in heated oxygen sensor output line
Engine control module failed
Both have something to do with running lean, or the o2 sensor running so cold, that it reads lean (even if you're not).
I would check the O2 sensor wiring for the proper 5V feed for the heating element. If you're not getting 5V then you'll have to go back and check the wiring to figure out where the fault is.
If you DO have 5V, then the problem is it's reading lean. You need to figure out WHY it's reading lean.
Thread Starter
Senior Member
Joined: Jun 2010
Posts: 117
Likes: 0
From: atx!!
Vehicle: 2000 hyundai tiburon
REDZ, headers are good- no cracks.
Im replacing the maf very soon. Should have it in a few days.
Where does the neg. wire ground ground off at?
Did research, found the ecu and a bunch of wires up above the fuse box.
Dont know which are the o2 wires.
Where do I purchase a multimeter at?
Im going out right now to check fo vacuum leaks and see if I can find the neg.
wire for the o2 sensor.
One other thing, I started my car yesterday coming home from work at about 5:30 pm
and the died on me. so I started it back up and it it didnt want to idle at normal rpm so I
had to keep it at least 2000 rpm so it wouldnt drop to low rpm and die. But after warmed up
ran fine. Cuold this be the TPS becuase I looked at the name and it said dae sung or
something like that. THANK all of you for being supportive.....will let you know how things go.
Im replacing the maf very soon. Should have it in a few days.
Where does the neg. wire ground ground off at?
Did research, found the ecu and a bunch of wires up above the fuse box.
Dont know which are the o2 wires.
Where do I purchase a multimeter at?
Im going out right now to check fo vacuum leaks and see if I can find the neg.
wire for the o2 sensor.
One other thing, I started my car yesterday coming home from work at about 5:30 pm
and the died on me. so I started it back up and it it didnt want to idle at normal rpm so I
had to keep it at least 2000 rpm so it wouldnt drop to low rpm and die. But after warmed up
ran fine. Cuold this be the TPS becuase I looked at the name and it said dae sung or
something like that. THANK all of you for being supportive.....will let you know how things go.
Senior Member
Joined: Jul 2004
Posts: 5,155
Likes: 0
From: Eau Claire, WI
Vehicle: 97 Tib
yes, 90% of problems like that are TPS related. even if that's not what caused it right now, the dae sung WILL give you issues later on. you can try to get it replaced for free by your dealer (it was a TSB but never an official recall), some dealers will and some won't.
from Korea they are $45 new...I can try looking at the yards for you, i check the yards around here every couple weeks and see if i can pull anything, usually end up finding a TPS and selling it for like $25
BTW, you want a KEFICO TPS, NOT a Dae Sung.
Remember, on the o2 sensor there are 4 wires.
Power wire +5v
Positive signal wire +
Negative signal wire -
Ground wire -
More info from Mr Random:
Now, it COULD be the ECU is the problem, but that's not very likely. Chances are it's your wiring somewhere. You need to verify that you're getting 5volts running (from the ECU) to the First o2 sensor.
So, start testing the wires at the very front of the First o2, you need to get 5volts at the WIRING CONNECTOR of the first o2. If you don't have it, keep following the wiring BACK toward the ECU, UNTIL you pick up 5V. IF you follow it all the way back to the ECU and you STILL don't have 5V. Then you KNOW its the ECU's fault, and not the o2 sensor's fault.
Keep in mind that the signal wires only carry between .1V and 1.3V That's it.
If you're getting .1 to 1.3V that's oscilating, those are the signal wires. This doesn't help you, you need to worry about the other 2 wires.
You can get a multimeter almost anywhere...
radio shack, walmart, best buy, etc.
from Korea they are $45 new...I can try looking at the yards for you, i check the yards around here every couple weeks and see if i can pull anything, usually end up finding a TPS and selling it for like $25
BTW, you want a KEFICO TPS, NOT a Dae Sung.
Remember, on the o2 sensor there are 4 wires.
Power wire +5v
Positive signal wire +
Negative signal wire -
Ground wire -
More info from Mr Random:
Now, it COULD be the ECU is the problem, but that's not very likely. Chances are it's your wiring somewhere. You need to verify that you're getting 5volts running (from the ECU) to the First o2 sensor.
So, start testing the wires at the very front of the First o2, you need to get 5volts at the WIRING CONNECTOR of the first o2. If you don't have it, keep following the wiring BACK toward the ECU, UNTIL you pick up 5V. IF you follow it all the way back to the ECU and you STILL don't have 5V. Then you KNOW its the ECU's fault, and not the o2 sensor's fault.
Keep in mind that the signal wires only carry between .1V and 1.3V That's it.
If you're getting .1 to 1.3V that's oscilating, those are the signal wires. This doesn't help you, you need to worry about the other 2 wires.
You can get a multimeter almost anywhere...
radio shack, walmart, best buy, etc.
Thread Starter
Senior Member
Joined: Jun 2010
Posts: 117
Likes: 0
From: atx!!
Vehicle: 2000 hyundai tiburon
I got the multimeter and checked the voltage of the plug going out to the o2 sensor from the ECU . The readings came back as:
Yellow: .74
Brown: .28
Green: .01-.02
Red w/ white stripe: 12.43
I checked with the multimeter setting on DC 20 V. I put the negative probe on the negative side of the battery and touched the positive probe to the different wires listed above. Also I turned the ignition key on to get these readings. Did I do this right?
I looked at the air intake hose that connects to the tb and I found a hole on the back side of it. It looks as though someone drilled it and found another hole on the air intake bypass hose. I'll be replacing it tommorrow. I will keep you updated on this.
Does any one have a TPS or know where I can get one?
Yellow: .74
Brown: .28
Green: .01-.02
Red w/ white stripe: 12.43
I checked with the multimeter setting on DC 20 V. I put the negative probe on the negative side of the battery and touched the positive probe to the different wires listed above. Also I turned the ignition key on to get these readings. Did I do this right?
I looked at the air intake hose that connects to the tb and I found a hole on the back side of it. It looks as though someone drilled it and found another hole on the air intake bypass hose. I'll be replacing it tommorrow. I will keep you updated on this.
Does any one have a TPS or know where I can get one?
Senior Member
Joined: Aug 2004
Posts: 560
Likes: 0
From: syracuse new york
yes i had the same codes my wire was messed up and the p131 code went away,the other code is still there and my gas is crazy bad. I changed my tps,maf,o2 and still same code been like this for months.pisses me off any luck please post so maby i can solve my problem.
