P 0420 Again
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Veteran
Joined: Feb 2012
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From: Missouri
P 0420 Again
I was going down the road and the light randomly came on. I did the keydance and got 0420 which I understand is the "cat is not good enough" code. I went home and hooked up my scan tool and got these values for the two O2 sensors.
"Sensor 1"
"Sensor 2"
Is my Cat really bad? What do these values mean?
"Sensor 1"
Code:
Movi Live Data 2012-11-20 15:58:04 Time(seconds) Volts, % 108.054748 0.705, -1.56 108.487924 0.155, 0.00 108.937940 0.705, -0.78 109.370686 0.725, -1.56 109.803333 0.450, -0.78 110.238715 0.115, 0.78 110.676869 0.665, -0.78 111.126723 0.155, 0.78 111.562416 0.095, 2.34 111.996585 0.800, 0.00 112.424655 0.800, -0.78 112.859567 0.135, 1.56 113.295504 0.370, 2.34 113.729256 0.840, 0.00 114.165117 0.780, -0.78 114.597285 0.195, 1.56 115.035824 0.800, -0.78 115.464675 0.800, -0.78 115.899988 0.525, -0.78 116.334195 0.135, 1.56 116.769101 0.625, 0.78 117.184526 0.820, 0.00 117.622606 0.585, 0.00 118.054744 0.135, 2.34 118.486314 0.800, -0.78 118.920850 0.760, -0.78 119.356688 0.215, 0.78 119.761347 0.545, 0.78 120.160139 0.800, -0.78 120.594256 0.505, 0.00 121.028609 0.115, 2.34 121.465028 0.800, 0.00 121.898867 0.800, -0.78 122.333954 0.665, -0.78 122.780794 0.175, 0.78 123.230543 0.820, -0.78 123.664124 0.290, 0.00 124.116605 0.250, 1.56 124.550937 0.820, -0.78 124.985657 0.745, -1.56 125.418741 0.330, 0.00 125.856351 0.155, 0.78 126.288474 0.250, 0.78 126.723378 0.800, -0.78 127.160940 0.800, -1.56 127.591194 0.195, 0.00 128.024497 0.585, 0.00 128.476226 0.820, -1.56 128.908472 0.270, 0.00 129.343881 0.235, 0.78 129.776788 0.800, -1.56 130.211366 0.585, -1.56 130.646053 0.235, 0.00 131.080067 0.760, -1.56 131.519474 0.780, -2.34 131.948013 0.625, -2.34 132.383500 0.095, 0.78 132.816392 0.820, -1.56 133.250462 0.725, -1.56 133.673453 0.290, -0.78 134.103253 0.235, 0.78 134.558280 0.525, -0.78 134.996049 0.760, -1.56 135.440387 0.175, 0.00 135.874905 0.310, 0.78 136.307490 0.820, -1.56 136.741724 0.665, -1.56 137.175670 0.705, -1.56 137.610370 0.505, -1.56 138.044143 0.585, -0.78 138.478789 0.745, -2.34 138.917113 0.115, 0.00 139.345933 0.625, -0.78 139.785197 0.800, -2.34 140.253881 0.665, -2.34 140.683118 0.095, 0.78 141.121332 0.800, -1.56 141.538549 0.760, -2.34 141.969376 0.155, 0.00 142.424141 0.800, -1.56 142.853488 0.780, -2.34 143.288483 0.095, 0.00 143.724726 0.685, -0.78 144.158151 0.780, -1.56 144.595514 0.760, -2.34 145.028538 0.605, -1.56 145.463326 0.665, -2.34 145.893997 0.175, -0.78 146.331707 0.820, -2.34 146.761025 0.545, -2.34 147.195996 0.135, 0.00 147.620943 0.780, -2.34 148.086124 0.725, -2.34 148.515851 0.095, 0.00 148.950100 0.645, -0.78 149.387077 0.820, -2.34 149.823583 0.235, -0.78 150.272457 0.645, -0.78 150.702559 0.800, -2.34 151.138509 0.470, -2.34 151.570620 0.155, 0.00 152.006431 0.760, -2.34 152.440977 0.585, -2.34 152.874479 0.115, 0.00 153.309094 0.780, -2.34 153.769364 0.780, -2.34 154.210304 0.290, -1.56 154.644016 0.685, -2.34 155.079146 0.725, -3.12 155.513096 0.095, 0.00 155.950489 0.780, -2.34 156.381691 0.685, -2.34 156.816284 0.075, 0.78 157.249985 0.820, -1.56 157.683868 0.760, -2.34 158.123009 0.215, -0.78 158.558175 0.525, 0.00 159.003919 0.800, -1.56 159.436786 0.685, -2.34 159.872666 0.270, -0.78 160.327592 0.390, 0.00 160.757964 0.820, -2.34 161.192655 0.585, -2.34 161.626702 0.310, 0.00 162.063887 0.800, -2.34 162.496501 0.645, -3.12 162.928614 0.115, 0.00 163.366498 0.820, -2.34 163.796287 0.685, -2.34 164.230053 0.115, 0.00 164.669326 0.800, -2.34 165.097837 0.370, -1.56 165.533925 0.095, 0.78 165.966719 0.840, -1.56 166.417539 0.760, -2.34 166.854448 0.115, 0.00 167.287017 0.800, -1.56 167.725756 0.725, -2.34 168.160381 0.155, 0.00 168.594437 0.780, -2.34 169.024360 0.725, -3.12 169.458921 0.115, 0.00 169.896900 0.820, -2.34 170.331044 0.800, -2.34 170.760508 0.195, -1.56 171.194929 0.490, 0.00 171.634594 0.800, -2.34 172.064888 0.350, -1.56 172.500624 0.135, 0.78 172.935651 0.800, -1.56 173.337333 0.645, -2.34 173.783630 0.175, 0.00 174.216889 0.800, -2.34 174.652306 0.685, -2.34 175.091155 0.135, 0.00 175.519225 0.780, -2.34 175.954601 0.330, -0.78 176.388042 0.270, 0.00 176.826045 0.800, -2.34 177.258320 0.095, 0.00 177.692192 0.840, -1.56 178.125820 0.745, -2.34 178.558475 0.175, 0.00 178.998332 0.800, -1.56 179.426532 0.705, -2.34 179.862094 0.075, 0.78 180.297429 0.820, -0.78 180.730389 0.760, -1.56 181.165508 0.195, 0.00 181.598299 0.135, 1.56 182.034468 0.800, -0.78 182.473181 0.705, -1.56 182.906372 0.270, 0.00 183.337238 0.585, 0.00 183.770328 0.760, -2.34 184.204954 0.175, 0.00 184.639581 0.800, -2.34 185.052605 0.800, -3.12 185.495725 0.135, -0.78 185.928694 0.310, 0.00 186.359892 0.760, -1.56 186.794029 0.235, -0.78 187.227331 0.250, 0.78 187.660126 0.820, -1.56 188.096033 0.780, -1.56 188.530597 0.075, 0.78 188.963675 0.705, 0.00 189.398895 0.800, -0.78 189.810715 0.075, 1.56 190.251002 0.525, 0.78 190.683999 0.840, -0.78 191.118706 0.745, -0.78 191.557076 0.175, 0.78 192.002770 0.800, -0.78 192.412615 0.760, -0.78 192.855510 0.450, 0.00 193.290288 0.175, 0.78 193.724882 0.800, -0.78 194.158051 0.725, -1.56 194.590450 0.175, 0.00 195.028598 0.250, 0.78 195.461640 0.800, -1.56 195.896575 0.135, 0.00 196.334291 0.115, 2.34 196.762989 0.840, -0.78 197.196059 0.760, -0.78 197.635855 0.155, 1.56 198.073075 0.820, -0.78 198.533398 0.745, -0.78 198.969878 0.705, -1.56 199.418668 0.135, 0.00 199.870122 0.525, 0.78 200.303773 0.820, -0.78
Code:
Movi Live Data 2012-11-20 15:58:05 Time(seconds) Volts, % 108.187483 0.800 108.635294 0.780 109.066734 0.725 109.503583 0.800 109.938353 0.800 110.373505 0.745 110.810866 0.780 111.260239 0.780 111.695251 0.290 112.130390 0.760 112.558074 0.800 112.991919 0.800 113.430497 0.725 113.862816 0.820 114.295376 0.820 114.735238 0.800 115.168538 0.800 115.598415 0.800 116.035378 0.800 116.467473 0.685 116.900910 0.625 117.318073 0.800 117.758143 0.800 118.189337 0.780 118.622197 0.800 119.060872 0.820 119.460914 0.780 119.895584 0.685 120.295277 0.820 120.722470 0.800 121.160234 0.760 121.597561 0.820 122.023171 0.820 122.484415 0.820 122.919179 0.800 123.365579 0.820 123.806387 0.800 124.249125 0.760 124.683949 0.820 125.118668 0.820 125.552491 0.800 125.988448 0.780 126.425052 0.800 126.852441 0.800 127.291561 0.820 127.727963 0.800 128.160058 0.760 128.607547 0.820 129.042760 0.800 129.481203 0.780 129.909514 0.820 130.346333 0.800 130.779760 0.800 131.212952 0.780 131.651877 0.780 132.079992 0.800 132.515531 0.585 132.949422 0.665 133.384781 0.820 133.806246 0.780 134.253665 0.665 134.691276 0.800 135.142970 0.780 135.575197 0.780 136.011575 0.725 136.441513 0.820 136.875576 0.820 137.307466 0.800 137.743117 0.780 138.177293 0.760 138.615723 0.800 139.049723 0.780 139.478713 0.705 139.944200 0.820 140.386308 0.800 140.817165 0.745 141.233048 0.780 141.672596 0.820 142.103498 0.780 142.558744 0.800 142.987853 0.820 143.421118 0.800 143.853815 0.505 144.295825 0.820 144.729107 0.800 145.162370 0.800 145.597626 0.780 146.027886 0.760 146.465506 0.800 146.896304 0.820 147.330699 0.780 147.771611 0.800 148.219797 0.820 148.650525 0.780 149.083401 0.490 149.522041 0.820 149.971781 0.800 150.402226 0.685 150.836651 0.820 151.271347 0.800 151.705655 0.760 152.140828 0.800 152.577203 0.800 153.008167 0.745 153.442497 0.780 153.913684 0.800 154.343784 0.780 154.779027 0.725 155.210704 0.800 155.647236 0.760 156.079793 0.705 156.516379 0.800 156.953828 0.665 157.383738 0.665 157.817163 0.800 158.256637 0.780 158.705735 0.745 159.136318 0.820 159.571416 0.800 160.010659 0.800 160.459699 0.605 160.890925 0.800 161.329168 0.800 161.762197 0.745 162.196416 0.800 162.632266 0.800 163.060554 0.645 163.499632 0.780 163.930735 0.800 164.365479 0.725 164.803253 0.780 165.232854 0.800 165.665271 0.585 166.101463 0.780 166.551470 0.800 166.991274 0.760 167.419991 0.800 167.860135 0.800 168.292769 0.780 168.726624 0.780 169.157108 0.820 169.595651 0.780 170.030372 0.760 170.463086 0.820 170.894477 0.800 171.330124 0.605 171.767553 0.800 172.201312 0.800 172.634220 0.705 173.069400 0.800 173.471194 0.800 173.917257 0.780 174.351922 0.800 174.784115 0.820 175.223776 0.780 175.653845 0.780 176.088558 0.800 176.521301 0.705 176.960692 0.800 177.391032 0.760 177.824531 0.705 178.264035 0.800 178.697761 0.745 179.130465 0.800 179.562118 0.800 179.995741 0.505 180.429703 0.505 180.864959 0.800 181.297595 0.800 181.733511 0.390 182.170975 0.780 182.606827 0.800 183.038190 0.780 183.470291 0.760 183.902755 0.800 184.338215 0.760 184.772804 0.725 185.194328 0.800 185.631615 0.780 186.062890 0.235 186.491053 0.625 186.926876 0.760 187.360621 0.250 187.796172 0.745 188.234305 0.780 188.662352 0.450 189.099166 0.215 189.531214 0.780 189.953459 0.665 190.384550 0.270 190.817343 0.800 191.252593 0.800 191.691629 0.780 192.137348 0.760 192.559652 0.820 192.990068 0.800 193.422135 0.780 193.861464 0.780 194.291444 0.800 194.725689 0.800 195.164458 0.745 195.595351 0.820 196.034462 0.800 196.465818 0.430 196.896651 0.800 197.330599 0.800 197.769859 0.800 198.221934 0.800 198.666844 0.820 199.103006 0.800 199.560835 0.780 200.003601 0.290 200.437806 0.800
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Could be an 02 sensor.
e:
A code P0420 may mean that one or more of the following has happened:
e:
A code P0420 may mean that one or more of the following has happened:
- Leaded fuel was used where unleaded was called for
- A damaged or failed oxygen sensor (HO2S)
- Downstream oxygen sensor (HO2S) wiring damaged or connected improperly
- The engine coolant temperature sensor is not working properly
- Damaged or leaking exhaust manifold / catalytic converter / muffler / exhaust pipe
- Retarded spark timing
- The oxygen sensors in front and behind the converter are reporting too similar of readings
- Leaking fuel injector or high fuel pressure
- Cylinder misfire
- Oil contamination
Last edited by George Dorn; Nov 20, 2012 at 05:22 PM.
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02S2 is switching quite frequently near the end of your recording. So if the downstream 02 sensor is switching it usually means the catalyst isn't catalyzing... but it sure would be nice to see what the rest of the engine was doing when the downstream was switching.
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From: Missouri
What exactly do you mean? I can run another report. RPM? Coolant Temp? IAT, MAP? From the look of all the readings, the values from the upstream and downstream O2s are very similar through out. Thus the Cat isn't working?
Last edited by fhadso; Nov 20, 2012 at 11:27 PM.
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Not near the end of your recording. The downstream started switching with the upstream. The rear 02 should barely ever move. It would be nice to see fuel trims and misfire monitor along with RPM and ECT. So my question is did the rear continue to switch even more as the you were looking at it?
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