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Why might an '89 Honda Civic fail an emissions test 3 times because of high readings on idling after changing the O2 sensor and catalytic converter?
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Answered 2004-09-17 00:10:15
Depends on which of the readings failed. Was it CO (carbon monoxide), HC (hydrocarbons), NOx (nitrous of oxides), or a combination of them?
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Will the GReddy Ti-C Catback Exhaust System for 06-09 Honda Civic affect my emissions reading?
The GReddy Ti-C Catback Exhaust System will have absolutely no effect on emissions readings because it retains the stock catalytic converter.
Can replacing the flange gasket to exhaust manifold clear a p0420?
Not likely because: Code p0420 refers to a problem with your catalytic converter. The engine computer is able to test that converter by using an oxygen sensor before and after the converter. The computer can only test the converter under very specific driving conditions. If the computer determines that it is a good time to test the catalytic converter it will run the test. It compares the oxygen sensor readings in front of the converter to the readings behind the converter to see if the catalytic converter is functioning properly. If it is not functioning properly it will trigger a p0420. Sometimes if a catalytic converter is on the virge of failing it may fail one test and pass the next. This will cause your check engine light to come off and on every once in a while when the test is performed.
Is the 02 sensor connected to the vent solenoid?
O2 (oxygen) sensors come in pairs. One is placed before the catalytic converter to get an exhaust reading for unused fuel vapors. The other is placed after the converter to measure the same. The on board computer compares the two readings to make sure the converter is working (heating up to burn unused gas vapors for cleaner emissions).
What happens when you remove the catalytic converter from a 2005 silverado?
Check engine light will come on due to bad readings from oxygen sensor after cat
What is the working principle of oxygen analyzer?
Sensor 1 (before the catalytic converter) adjusts the fueling based on sensing if the engine is burning fuel rich or lean. The post-converter sensor detects if the converter is operating properly by looking for a difference in readings
Can you eliminate the catalytic converter on a 2004 impala?
NO. It is illegal, can cause low power and poor fuel economy as the computer tries to adjust for the improper readings from the O2 sensors.
Can your car run better without a catalytic converter?
absolutely it will have more power however it wont pass the smog If it is a 1996 or later model the computer will try to adjust for the incorrect oxygen sensor readings ,due to the missing cat. This can and will hurt power and economy. Plus it is very illegal to remove a catalytic converter.
Will removing catalytic converter have negative effects on an engine?
As far as the environment is concerned, yes. Catalytic converters are very important in regulating the amount of pollution your vehicle emits. As far as vehicle performance, removing a catalytic converter could increase horsepower and exhaust flow. Removing the converter can (and does on most) cause the computer to over-correct for the improper oxygen sensor readings. This over-correction usually causes a reduction in power, economy, and running performance. It is also highly illegal.
Can you remove the catalytic converter if the sensors is before and after the cat?
No. It is not legal. The check engine light will turn on. The computer will try to correct for improper sensor readings and that will cause fuel economy and performance issues.
What are exhaust gases maximum allowable readings for a fuel injected vehicle equipped with a catalytic converter?
the five exhaust gases are carbon monoxide, carbon dioxide, oxygen, nitrogen oxides and unburned hydrocarbon
What is DTC PO420 on a 2000 Camaro?
P0420 usually points to a failed catalytic converter, if the exhaust system is intact, that is. Exhaust leaks in front of a catalytic converter can affect the O2 readings and at times throw a false code. P0141 indicates only the heater circuit of the o2 sensor has a problem. Usually it's the element in the sensor, and replacing the sensor would fix that, but it doesn't rule out a harness issue or a short in the wiring
Is there a connection between Cat failure and code P1456 you replaced your exhaust after the reading stated a replacement of Catalytic converter After several Months the engine light came back onP1456?
You will have to figure this out for your self but how to think about this. There are two Oxegen Sensors in the exhaust. One on each side of the Catalyic converter. The difrence in readings is how the system checks the Cat. If you took out the Catalist and replaced with a straight pipe you get trhis code. There is a simple way around it by installing a resistor in the wiring to the rear cat. But that is not going to pass emissions testing.
Check engine light: Reading stated catalyst effeciency below threshold?
The catalyst moniter is the rear oxygen sensor located after the catlytic converter. It sole job is to moniter whether the cat is performing corectly. It does this by comparing it's gas readings to the front (before cat) oxygen sensor readings. If it sees readings too similar to that of the front sensor, the vehicles computer(PCM) concludes that the cats are not changing the exaust gases thus are not doing their job. A catalyst moniter code can be set for 2 reasons. 1) that the catalyst moniter has failed (not typical) or 2) that the catalytic converter has lost it's catalystic properties, and is no longer working. This latter is usually the case, and requires the replacement of the catalytic converter. You can diagnose a failed cat with a scan tool that is equipped with scan display data. You can watch the voltages from the front and rear O2 sensors, after fully warming up the engine, and see if they follow each other too closely. It will be appearant, because if the catalytic converter is working properly, the rear O2 sensor will switch will have very little fluctuation in voltage, while the front will be constantly switching from near o volts to nearly a volt, several times a minute.
How will removal of the catalytic converter affect a 1998 Jeep Cherokee Sport?
It will cause the check engine light to stay on, and may also cause performance issues as the computer tries to adjust the O2 sensor readings to the proper level. Plus it is highly illegal
Is there a difference between the 2 O2 sensors on the 2.5L 2002 Sentra?
The first sensor senses if the engine is running rich or lean so the ecu can adjust the fueling. The second sensor looks for a difference in readings to verify the catalytic converter is functioning properly
You bought a used car 2 weeks ago and you got a 3 month warranty on engine and gearbox and now the catalytic converter is gone do you have any comeback with the garage?
Yes!!!, The catalytic converter (CC) should not have anything wrong with it if the engine was tuned correctly. If the engine was running rich, because the computer was compensating for a sensor that is giving incorrect readings then the CC would clog with the carbon produced by running too rich. This is the most common cause of CC failure.
What problems are caused by no catalytic converter?
Check engine light,low power, low fuel economy, (when the computer tries to adjust the oxygen sensor readings)highly illegal.Check engine light,low power, low fuel economy, (when the computer tries to adjust the oxygen sensor readings)highly illegal.
What is code p0644 on a 1996 Lexus es300?
The catalytic converter has an oxygen sensor in front and behind it. When the vehicle is warm and running in closed loop mode, the upstream oxygen sensor waveform reading should fluctuate. The downstream O2 sensor reading should be fairly steady. Typically the p0420 code triggers the Check Engine Light if the readings of the two sensors are similar. This is indicative of (among other things) a converter that is not working as efficiently as it should be (according to specs). The code P0420 may mean that one or more of the following has happened: Leaded fuel was used where unleaded was called for, an oxygen sensor is not reading (functioning) properly, the engine coolant temperature sensor is not working properly, damaged or leaking exhaust manifold/catalytic converter/exhaust pipe, retarded spark timing, the oxygen sensors in front and behing the converter are reporting too similar of readings
What happens when catalytic converter is removed?
ON a computer control ed fuel system the computer tries to adjust fuel and ignition timing for the now improper oxygen sensor readings. This tends to cause a reduction in power, fuel economy, and how smooth the engine is. It is also illegal and will turn the check engine light on.
How can changing air pressure be used to predict changing weather conditions?
As high and low - pressure areas move the barometer readings in their paths change.
How do you repair a p0420 on a 2001 buick lasabre?
This is what I was able to find via some good ol fashion detective work. This came off of FixYa.com. Hope it helps.A code P4020 may mean that one or more of the following has happened:Leaded fuel was used where unleaded was called forAn oxygen sensor is not reading (functioning) properlyThe engine coolant temperature sensor is not working properlyDamaged or leaking exhaust manifold / catalytic converter / exhaust pipeRetarded spark timingThe oxygen sensors in front and behind the converter are reporting too similar of readingsPossible Solutions Some suggested steps for troubleshooting a P4020 error code include:Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady).Inspect the downstream heated oxygen sensor (HO2), replace if necessaryReplace the catalytic converterOne thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into
What causes high CO readings in auto emissions test results?
High CO is a rich air/fuel mixture. Nothing else.
What does an O2 sensor do on a 02 Jeep Cherokee?
It measures the amount of hydrocarbons in the exhaust and reports the difference between the readings from the pre and post catalytic sensors to give tuning information to the engine control computer, adjustments are made to timing and fuel based on the readings.
Can you run a straight pipe and cut the catalytic converter on 2001 grand am?
No!It is illegal.The check engine light will always stay on.The engine may actually run worse due to the computer trying to correct oxygen sensor readings and the change in exhaust back pressure.No!It is illegal.The check engine light will always stay on.The engine may actually run worse due to the computer trying to correct oxygen sensor readings and the change in exhaust back pressure.
odometer readings ?
where can i get free odometer readings?
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