O2 sensor What does the 02 sensor do? What problems can it cause if it is not working properly? How can you tell which one is bad? Can it affect the shifting of the transmission going into passing gear?

These may be few possible reasons why the check engine light won't go away after replacing the O2 sensor in your 2000 Mitsubishi Eclipse V6

·The wrong O2 sensor was replaced or the O2 sensor is properly connected to the wiring harness(any signs of damage or corrosion).
·Sometimes, issues with the engine, such as misfires, vacuum leaks, or problems with the fuel system, can trigger the O2 sensor to report a problem. Ensure your engine is running smoothly and there are no other issues that could affect air/fuel ratios.
·The new O2 sensor is defective. If the O2 sensor is working properly, then the check engine light could be due to another problem with the exhaust system, such as a leak or a problem with the catalytic converter.
·Problem with the wiring to the O2 sensor. If the wiring to the O2 sensor is damaged or corroded, it can cause the sensor to malfunction and trigger the check engine light. To diagnose the exact cause of the problem, you will need to have the car scanned by a qualified mechanic. The mechanic will be able to read the trouble codes from the computer and use that information to pinpoint the problem.

do you want gue$$ or how to test using TOOLS?
4 engines but told it YEAH. 3.2L
check all fuses first. a 20cent part, we test them 1 of 3 ways (ask)
flashing CEL means , CATS are going to run way too hot and may be damaged, means dont drive it far.

you failed to tell the 4 O2 DTC errors..
there are 2 kinds, heater or sensor out (cell) voltage
which one is key to the problem why do that>?
O2 sensors all 4 failing to me (blind) smacks of heaters shorted. (or the wires to them 1 wire shorted can short them all out) and is never good this.
you have p0300 errors to, ? or just 1 code p030x
where x is a number 1 to 6 and is always the same exact number, again no DTC told just vague.
questions all I have are those, blind must ask them ok.?
ever get a full tuneup 19 years.?
for sure spark plugs and filters and fan belt.(serp)
on this 3.2L the O2 heaters shorted blow 2 fuses
pre O2 or Post 02 fuses. so seems not this. hoodbox

ESP mind meld 1:
misfire codes P030x (x = 0 to max or 6)
if one fails it means that cylinder # has weak
combustion. or if p0300 all are.
caused by
that cylinders is bad, (example burned head valves)
and low compression tests (below 150psi) or vacuum test gauge shows, vacuum bouncing like mad,. oops
bad engine.

or bad spark (never did a tune up here ,bingo)
and last bad fueling if fuel is too lean on all 6
we see po300 and lean burn codes p017x or LTFT long term fuel trim way off at +xx huge %
or too rich fuel and misfires (on all or just 1 cyl)
or just one injector is dead , leaks or is 1/2 clogged

lacking any list of all DTC failing,all i can do is say how to do the tests. (engine,spark ,fueling)
scan the PCM
write down all DTC found
and share them all, skip none..

These 2 articles are from another source. They explain exactly what all the causes and cures are for your Codes. The problem seems to be on the #2 bank. P0130 - 02 Sensor Circuit Malfunction (Bank I Sensor 1) Article by

Dale Toalston
ASE Certified Technician OBD-II Trouble Code Technical Description

02 Sensor Circuit Malfunction (Bank I Sensor 1)
What does that mean? The O2 sensor produces a voltage based on oxygen content in the exhaust. The voltage varies between .1 and .9 Volts, .1 indicating lean and .9 indicating rich.
The ECM constantly monitors this voltage while in closed loop to determine how much fuel to inject. If the ECM determines that the O2 sensor voltage was too low (less than .4 Volts) for too long (for more than 20 seconds (time varies with model)), this code is set.
Potential Symptoms Depending if the problem is intermittent or not, there may be no symptoms other than MIL (malfunction indicator lamp) illumination. If the problem is constant, then symptoms may include one or more of the following:

• MIL illumination
• Engine runs rough, missing or stumbling
• Blows black smoke from tail pipe
• Engine dies
• Poor fuel economy

Causes Usually the cause of P0130 is a bad oxygen sensor, however this isn't always the case. If your o2 sensors haven't been replaced and they are old, it's a good bet that the sensor is the problem. But, It could be caused by any of the following:

• Water or corrosion in the connector
• Loose terminals in the connector
• Wiring burnt on exhaust components
• Open or short in the wiring due to rubbing on engine components
• Holes in exhaust allowing unmetered oxygen into exhaust system
• Unmetered vacuum leak at the engine
• Bad o2 sensor
• Bad PCM

Possible Solutions Using a scan tool, determine if the Bank 1, sensor 1 is switching properly. It should switch rapidly between rich and lean, evenly.
1. If it does, the problem is likely intermittent and you should examine the wiring for any visible damage. Then perform a wiggle test by manipulating the connector and wiring while watching the o2 sensor voltage. If it drops out, fix the appropriate part of the wiring harness where problem resides.
2. If it doesn't switch properly, try to determine if the sensor is accurately reading the exhaust or not. Do this by removing the fuel pressure regulator vacuum supply briefly. The o2 sensor reading should go rich, reacting to the extra fuel added. Reinstall regulator supply. Then induce a lean condition by removing a vacuum supply line from the intake manifold. The o2 sensor reading should go lean, reacting to the enleaned exhaust. If the sensor operates properly, then the sensor may be okay and the problem may be holes in the exhaust or an unmetered vacuum leak in the engine (NOTE: Unmetered vacuum leaks at the engine are almost always accompanied by lean codes. Refer to the appropriate articles for diagnosing an unmetered vacuum leak). If the exhaust does have holes in it, it's possible that the o2 sensor may be misreading the exhaust because of the extra oxygen entering the pipe via those holes
3. If none of this is the case and the o2 sensor just isn't switching or acts sluggish, unplug the sensor and make sure there is 5 Volt reference voltage to the sensor. Then check for 12V supply to the o2 sensor's heater circuit. Also check for continuity to ground on the ground circuit. If any of these are missing, or aren't their proper voltage, repair open or short in the appropriate wire. The o2 sensor will not operate properly without proper voltage. If the proper voltages are present, replace the o2 sensor.
Register now to ask a question (free) Related P0130 DTC Discussions P0150 - 02 Sensor Circuit Malfunction (Bank 2 Sensor 1) OBD-II Trouble Code Technical Description

02 Sensor Circuit Malfunction (Bank 2 Sensor 1)
What does that mean? The O2 sensor produces a voltage based on oxygen content in the exhaust. The voltage varies between .1 and .9 Volts, .1 indicating lean and .9 indicating rich.
The ECM constantly monitors this voltage while in closed loop to determine how much fuel to inject. If the ECM determines that the O2 sensor voltage was too low (less than .4 Volts) for too long (for more than 20 seconds (time varies with model)), this code is set. The code P0150 refers to Bank 2.
Potential Symptoms Depending if the problem is intermittent or not, there may be no symptoms other than MIL (malfunction indicator lamp) illumination. If the problem is constant, then symptoms may include one or more of the following:

• MIL illumination
• Engine runs rough, missing or stumbling
• Blows black smoke from tail pipe
• Engine dies
• Poor fuel economy

Causes Usually the cause of P0150 is a bad oxygen sensor, however this isn't always the case. If your o2 sensors haven't been replaced and they are old, it's a good bet that the sensor is the problem. But, It could be caused by any of the following:

• Water or corrosion in the connector
• Loose terminals in the connector
• Wiring burnt on exhaust components
• Open or short in the wiring due to rubbing on engine components
• Holes in exhaust allowing unmetered oxygen into exhaust system
• Unmetered vacuum leak at the engine
• Bad o2 sensor
• Bad PCM

Possible Solutions Using a scan tool, determine if the Bank 2, sensor 1 is switching properly. It should switch rapidly between rich and lean, evenly.
1. If it does, the problem is likely intermittent and you should examine the wiring for any visible damage. Then perform a wiggle test by manipulating the connector and wiring while watching the o2 sensor voltage. If it drops out, fix the appropriate part of the wiring harness where problem resides.
2. If it doesn\'t switch properly, try to determine if the sensor is accurately reading the exhaust or not. Do this by removing the fuel pressure regulator vacuum supply briefly. The o2 sensor reading should go rich, reacting to the extra fuel added. Reinstall regulator supply. Then induce a lean condition by removing a vacuum supply line from the intake manifold. The o2 sensor reading should go lean, reacting to the enleaned exhaust. If the sensor operates properly, then the sensor may be okay and the problem may be holes in the exhaust or an unmetered vacuum leak in the engine (NOTE: Unmetered vacuum leaks at the engine are almost always accompanied by lean codes. Refer to the appropriate articles for diagnosing an unmetered vacuum leak). If the exhaust does have holes in it, it's possible that the o2 sensor may be misreading the exhaust because of the extra oxygen entering the pipe via those holes
3. If none of this is the case and the o2 sensor just isn't switching or acts sluggish, unplug the sensor and make sure there is 5 Volt reference voltage to the sensor. Then check for 12V supply to the o2 sensor's heater circuit. Also check for continuity to ground on the ground circuit. If any of these are missing, or aren't their proper voltage, repair open or short in the appropriate wire. The o2 sensor will not operate properly without proper voltage. If the proper voltages are present, replace the o2 sensor.
Register now to ask a question (free) Related P0150 DTC Discussions

• 1996 Nissan Maxima P0150 P0136 P0105 P0130
  I own a 1996 Nissan Maxima, automatic, v6. Started to shut down on me when making stops. Always cranked back up. Changed out knock sensor, starter, air flow, battery cables...few other minor things. Still doing same thing but not near as often. After all this, codes read P0150, P0136 and P0105. Era...
  

the O2 sensor heater circuit is just what it says it is a heater fo the O2 sensor, it is there to make sure the sensor stays a constant temperature, the sensors like a lot of heat, if the heater is not working the sensor will not give proper info. about the amount of O2 ( oxygen ) in the exhaust flow which could cause the engine to run to rich or lean in either case the engine will not perform as good as it should and can cost you fuel mileage, it the worst case sanario the heater can short to the sensor return wire and cause all kinds of bad things to happen like cook the ECM, i suggest you replace the sensor, the #2 sensor will be the one after the catholic converter.

the code indicates a bank 1problem.so anything that is common between both sides of the motor will not set this code,if anything it would set a different code and show a common code for both sides of the motor,vacuum leak would not be the problem as it would also affect the way the motor runs,bad /dirty maf sensor again affects both sides and a code difference,bad coolant again affects both sides and different code,an 02 sensor can show which side the problem is and could cause the setting code.bad spark plugs can also cause this code, an injector one or more for this side can cause this,bad fuel pressure regulator will affect both sides again.so I would check spark plugs, check the 02 sensor for proper voltage readings on the left side of the motor(driver`s side),it`s uncommon for injectors on one side to only go bad and not injectors on both sides.if the plugs are okay and don`t need changing you may need to check for tune-up items such as plug wires.it sounds like the motor is not burning the fuel properly giving the rich running code

you have to figure out what is causing the 02 to activate the light, lean or rich exhaust emissions? what its saying is the sensor is working and it has detected a bad emissions or fuel mix in the exhaust, it is not telling you the 02 is bad, thats what the sensors do they detect faults with temps,knocks,emissions, timing,crank position, fuel air mix,throttle position. so the 02 is detecting something and that something is what needs to be found.

O2 sensors that are bad for awhile will affect the MAP sensor to go bad as well. Go to Auto Zone and they will provide a FREE scan of the engines computer. They will tell you what needs to be replaced or looked at

Typcally caused by one of the front oxygen sensors or a bad ground associated with these sensors.Replace both front sensors with direct fit type NOT universal, because there may be a cracked wire and the universal sensor does not contain the complete wire harness. Direct fits, are about $20 more than universal fit type.

The O2 sensors have integrated heating elements that bring them up to the proper operating temperature. Code P0431 indicates that the O2 sensor on your driver side catalytic converter is not reaching the proper operating range. The O2 sensors are usually in the $150 range online.

Code P0420 is a code for Catalyst efficiency. The computer is seeing the post Catalytic converter o2 sensor having too much activity. The Cat. should be cleaning the exaust of Hc, co, and Nox. The post cat o2 will read the o2 content in the exhaust and if it moves up and down too much or to high and low, the computer interperates that as the cat not ridding the exhaust of it's pollutants. This indicates that the converter is unable to preform properly. The problem could be a bad cat, o2 sensor (Pre- and/or post cat)or o2 sensor wires, or an air fuel mixture problem that has caused the cat to fail. Many other engine operating system failures can cause the converter to not work properly.

there are two 02 sensors actually on the engine. bank one is cylinders 1 3 5 bank 2 is 2 4 6. it controls the fuel to air ratio, if the O2 sensor is not working, the engine goes into limp mode, which means it is just putting as much fuel as possible into the cylinder, which will effect your gas mileage.

The O2 sensor may be fine, the pigtails off the 02 sensor go bad, the connection. I had in my car, i change the 02 sensor twice, then I found someone said the pigtails may be bad, so I cut the cars wiring harness pigtail, and the one coming off the 02 sensor, and directly wired it with the original truck 02 sensor, and it worked. all 02 sensors look similar, they screw in the side of the engine, and just have 4 wires coming off of it.

Try your origional one, and just bypassing the original wire connector, what I did was cut it off, skinned the wires, put some heat shrink rap on it, combined the wires together soldered them together, and heated the wire shrink rap, so that way it is water proof. car works perfect now.