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Posted on Mar 05, 2010
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I'm getting 3 codes on my Audi A6 po118 Coolant temp circuit high input po421 bank one warm up catalyst below thresh hold and po431 bank two warm up catalyst below thresh hold.

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john h

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  • Audi Master 29,494 Answers
  • Posted on Mar 05, 2010
john h
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Test the ect sensor wiring for loose or damaged connections and the sensor itself if bad replace the 421 and 431 codes might be related to the 118 code but test the o2 sensors and circuit wiring for damage or loose connections and also test cat converter may be clogging

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  • Contributor 7 Answers
  • Posted on Mar 05, 2010
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I have about 15 years experience with Audi/VW. The coolant issue is more like the result of the ECM coolant temp sensor failure. The Cat code might be the front oxygen sensor on that bank and not the front cat. If you need more information about this repair please fell free to contact me at [email protected], I have over 30 years of automotive experience to assist you, thanks.

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2004 Mazda 6 throwing code PO1410,PO171,PO174,PO421,PO431 Lunges while stopped in gear or idles up and down.

Start with the first code, most likely is causing the other codes. P1410 EGR Boost Solenoid Valve Stuck needs to be replaced. It's causing a vacuum leak.
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Where is the bank 1 sensor 1 air flow sensor located on a 2000 toyota avalon?

Sensor diagram for a 2000 toyota avalon and list of Pcodes dbd372cc-f8f3-49ef-b0c2-2adab46c4182.jpg 8fc069a5-bedc-447d-a1ef-4335798a0a0f.jpg

P0100 Mass or Volume Air Flow Circuit Malfunction
P0101 Mass or Volume Air Flow Circuit Range/Performance Problem
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
P0104 Mass or Volume Air Flow Circuit Intermittent
P0105 Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction
P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0109 Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
P0110 Intake Air Temperature Circuit Malfunction
P0111 Intake Air Temperature Circuit Range/Performance Problem
P0112 Intake Air Temperature Circuit Low Input
P0113 Intake Air Temperature Circuit High Input
P0114 Intake Air Temperature Circuit Intermittent
P0115 Engine Coolant Temperature Circuit Malfunction
P0116 Engine Coolant Temperature Circuit Range/Performance Problem
P0117 Engine Coolant Temperature Circuit Low Input
P0118 Engine Coolant Temperature Circuit High Input
P0119 Engine Coolant Temperature Circuit Intermittent
P0120 Throttle/Pedal Position Sensor/Switch "A" Circuit Malfunction
P0121 Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem
P0122 Throttle/Pedal Position Sensor/Switch "A" Circuit Low Input
P0123 Throttle/Pedal Position Sensor/Switch "A" Circuit High Input
P0124 Throttle/Pedal Position Sensor/Switch "A" Circuit Intermittent
P0125 Insufficient Coolant Temperature For Closed Loop Fuel Control
P0126 Insufficient Coolant Temperature For Stable Operation
P0130 O2Circuit Malfunction (Bank #1 Sensor #1)
P0131 O2Sensor Circuit Low Voltage (Bank #1 Sensor #1)
P0132 O2Sensor Circuit High Voltage (Bank #1 Sensor #1)
P0133 O2Sensor Circuit Slow Response (Bank #1 Sensor #1)
P0134 O2Sensor Circuit No Activity Detected (Bank #1 Sensor #1)
P0135 O2Sensor Heater Circuit Malfunction (Bank #1 Sensor #1)
P0136 O2Sensor Circuit Malfunction (Bank #1 Sensor #2)
P0137 O2Sensor Circuit Low Voltage (Bank #1 Sensor #2)
P0138 O2Sensor Circuit High Voltage (Bank #1 Sensor #2)
P0139 O2Sensor Circuit Slow Response (Bank #1 Sensor #2)
P0140 O2Sensor Circuit No Activity Detected (Bank #1 Sensor #2)
P0141 O2Sensor Heater Circuit Malfunction (Bank #1 Sensor #2)
P0142 O2Sensor Circuit Malfunction (Bank #1 Sensor #3)
P0143 O2Sensor Circuit Low Voltage (Bank #1 Sensor #3)
P0144 O2Sensor Circuit High Voltage (Bank #1 Sensor #3)
P0145 O2Sensor Circuit Slow Response (Bank #1 Sensor #3)
P0146 O2Sensor Circuit No Activity Detected (Bank #1 Sensor #3)
P0147 O2Sensor Heater Circuit Malfunction (Bank #1 Sensor #3)
P0150 O2Sensor Circuit Malfunction (Bank #2 Sensor #1)
P0151 O2Sensor Circuit Low Voltage (Bank #2 Sensor #1)
P0152 O2Sensor Circuit High Voltage (Bank #2 Sensor #1)
P0153 O2Sensor Circuit Slow Response (Bank #2 Sensor #1)
P0154 O2Sensor Circuit No Activity Detected (Bank #2 Sensor #1)
P0155 O2Sensor Heater Circuit Malfunction (Bank #2 Sensor #1)
P0156 O2Sensor Circuit Malfunction (Bank #2 Sensor #2)
P0157 O2Sensor Circuit Low Voltage (Bank #2 Sensor #2)
P0158 O2Sensor Circuit High Voltage (Bank #2 Sensor #2)
P0159 O2Sensor Circuit Slow Response (Bank #2 Sensor #2)
P0160 O2Sensor Circuit No Activity Detected (Bank #2 Sensor #2)
P0161 O2Sensor Heater Circuit Malfunction (Bank #2 Sensor #2)
P0162 O2Sensor Circuit Malfunction (Bank #2 Sensor #3)
P0163 O2Sensor Circuit Low Voltage (Bank #2 Sensor #3)
P0164 O2Sensor Circuit High Voltage (Bank #2 Sensor #3)
P0165 O2Sensor Circuit Slow Response (Bank #2 Sensor #3)
P0166 O2Sensor Circuit No Activity Detected (Bank #2 Sensor #3)
P0167 O2Sensor Heater Circuit Malfunction (Bank #2 Sensor #3)
P0170 Fuel Trim Malfunction (Bank #1)
P0171 System Too Lean (Bank #1)
P0172 System Too Rich (Bank #1)
P0173 Fuel Trim Malfunction (Bank #2)
P0174 System Too Lean (Bank #2)
P0175 System Too Rich (Bank #2)
P0176 Fuel Composition Sensor Circuit Malfunction
P0177 Fuel Composition Sensor Circuit Range/Performance
P0178 Fuel Composition Sensor Circuit Low Input
P0179 Fuel Composition Sensor Circuit High Input
P0180 Fuel Temperature Sensor "A" Circuit Malfunction
P0181 Fuel Temperature Sensor "A" Circuit Range/Performance
P0182 Fuel Temperature Sensor "A" Circuit Low Input
P0183 Fuel Temperature Sensor "A" Circuit High Input
P0184 Fuel Temperature Sensor "A" Circuit Intermittent
P0185 Fuel Temperature Sensor "B" Circuit Malfunction
P0186 Fuel Temperature Sensor "B" Circuit Range/Performance
P0187 Fuel Temperature Sensor "B" Circuit Low Input
P0188 Fuel Temperature Sensor "B" Circuit High Input
P0189 Fuel Temperature Sensor "B" Circuit Intermittent
P0190 Fuel Rail Pressure Sensor Circuit Malfunction
P0191 Fuel Rail Pressure Sensor Circuit Range/Performance
P0192 Fuel Rail Pressure Sensor Circuit Low Input
P0193 Fuel Rail Pressure Sensor Circuit High Input
P0194 Fuel Rail Pressure Sensor Circuit Intermittent
P0195 Engine Oil Temperature Sensor Malfunction
P0196 Engine Oil Temperature Sensor Range/Performance
P0197 Engine Oil Temperature Sensor Low
P0198 Engine Oil Temperature Sensor High
P0199 Engine Oil Temperature Sensor Intermittent
P0200 Injector Circuit Malfunction
P0201 Injector Circuit Malfunction - Cylinder #1
P0202 Injector Circuit Malfunction - Cylinder #2
P0203 Injector Circuit Malfunction - Cylinder #3
P0204 Injector Circuit Malfunction - Cylinder #4
P0205 Injector Circuit Malfunction - Cylinder #5
P0206 Injector Circuit Malfunction - Cylinder #6
P0207 Injector Circuit Malfunction - Cylinder #7
P0208 Injector Circuit Malfunction - Cylinder #8
P0209 Injector Circuit Malfunction - Cylinder #9
P0210 Injector Circuit Malfunction - Cylinder #10
P0211 Injector Circuit Malfunction - Cylinder #11
P0212 Injector Circuit Malfunction - Cylinder #12
P0213 Cold Start Injector #1 Malfunction
P0214 Cold Start Injector #2 Malfunction
P0215 Engine Shutoff Solenoid Malfunction
P0216 Injection Timing Control Circuit Malfunction
P0217 Engine Over Temperature Condition
P0218 Transmission Over Temperature Condition
P0219 Engine Over Speed Condition
P0220 Throttle/Pedal Position Sensor/Switch "B" Circuit Malfunction
P0221 Throttle/Pedal Position Sensor/Switch "B" Circuit Range/Performance Problem
P0222 Throttle/Pedal Position Sensor/Switch "B" Circuit Low Input
P0223 Throttle/Pedal Position Sensor/Switch "B" Circuit High Input
P0224 Throttle/Pedal Position Sensor/Switch "B" Circuit Intermittent
P0225 Throttle/Pedal Position Sensor/Switch "C" Circuit Malfunction
P0226 Throttle/Pedal Position Sensor/Switch "C" Circuit Range/Performance Problem
P0227 Throttle/Pedal Position Sensor/Switch "C" Circuit Low Input
P0228 Throttle/Pedal Position Sensor/Switch "C" Circuit High Input
P0229 Throttle/Pedal Position Sensor/Switch "C" Circuit Intermittent
P0230 Fuel Pump Primary Circuit Malfunction
P0231 Fuel Pump Secondary Circuit Low
P0232 Fuel Pump Secondary Circuit High
P0233 Fuel Pump Secondary Circuit Intermittent
P0234 Engine Over Boost Condition
P0261 Cylinder #1 Injector Circuit Low
P0262 Cylinder #1 Injector Circuit High
P0263 Cylinder #1 Contribution/Balance Fault
P0264 Cylinder #2 Injector Circuit Low
P0265 Cylinder #2 Injector Circuit High
P0266 Cylinder #2 Contribution/Balance Fault
P0267 Cylinder #3 Injector Circuit Low
P0268 Cylinder #3 Injector Circuit High
P0269 Cylinder #3 Contribution/Balance Fault
P0270 Cylinder #4 Injector Circuit Low
P0271 Cylinder #4 Injector Circuit High
P0272 Cylinder #4 Contribution/Balance Fault
P0273 Cylinder #5 Injector Circuit Low
P0274 Cylinder #5 Injector Circuit High
P0275 Cylinder #5 Contribution/Balance Fault
P0276 Cylinder #6 Injector Circuit Low
P0277 Cylinder #6 Injector Circuit High
P0278 Cylinder #6 Contribution/Balance Fault
P0279 Cylinder #7 Injector Circuit Low
P0280 Cylinder #7 Injector Circuit High
P0281 Cylinder #7 Contribution/Balance Fault
P0282 Cylinder #8 Injector Circuit Low
P0283 Cylinder #8 Injector Circuit High
P0284 Cylinder #8 Contribution/Balance Fault
P0285 Cylinder #9 Injector Circuit Low
P0286 Cylinder #9 Injector Circuit High
P0287 Cylinder #9 Contribution/Balance Fault
P0288 Cylinder #10 Injector Circuit Low
P0289 Cylinder #10 Injector Circuit High
P0290 Cylinder #10 Contribution/Balance Fault
P0291 Cylinder #11 Injector Circuit Low
P0292 Cylinder #11 Injector Circuit High
P0293 Cylinder #11 Contribution/Balance Fault
P0294 Cylinder #12 Injector Circuit Low
P0295 Cylinder #12 Injector Circuit High
P0296 Cylinder #12 Contribution/Balance Fault
P0300 Random/Multiple Cylinder Misfire Detected
P0301 Cylinder #1 - Misfire Detected
P0302 Cylinder #2 - Misfire Detected
P0303 Cylinder #3 - Misfire Detected
P0304 Cylinder #4 - Misfire Detected
P0305 Cylinder #5 - Misfire Detected
P0306 Cylinder #6 - Misfire Detected
P0307 Cylinder #7 - Misfire Detected
P0308 Cylinder #8 - Misfire Detected
P0320 Ignition/Distributor Engine Speed Input Circuit Malfunction
P0321 Ignition/Distributor Engine Speed Input Circuit Range/Performance
P0322 Ignition/Distributor Engine Speed Input Circuit No Signal
P0323 Ignition/Distributor Engine Speed Input Circuit Intermittent
P0325 Knock Sensor #1 - Circuit Malfunction (Bank #1 or Single Sensor)
P0326 nock Sensor #1 - Circuit Range/Performance (Bank #1 or Single Sensor)
P0327 Knock Sensor #1 - Circuit Low Input (Bank #1 or Single Sensor)
P0328 Knock Sensor #1 - Circuit High Input (Bank #1 or Single Sensor)
P0329 Knock Sensor #1 - Circuit Input Intermittent (Bank #1 or Single Sensor)
P0330 Knock Sensor #2 - Circuit Malfunction (Bank #2)
P0331 Knock Sensor #2 - Circuit Range/Performance (Bank #2)
P0332 Knock Sensor #2 - Circuit Low Input (Bank #2)
P0333 Knock Sensor #2 - Circuit High Input (Bank #2)
P0334 Knock Sensor #2 - Circuit Input Intermittent (Bank #2)
P0335 Crankshaft Position Sensor "A" Circuit Malfunction
P0336 Crankshaft Position Sensor "A" Circuit Range/Performance
P0337 Crankshaft Position Sensor "A" Circuit Low Input
P0338 Crankshaft Position Sensor "A" Circuit High Input
P0339 Crankshaft Position Sensor "A" Circuit Intermittent
P0340 Camshaft Position Sensor Circuit Malfunction
P0341 Camshaft Position Sensor Circuit Range/Performance
P0342 Camshaft Position Sensor Circuit Low Input
P0343 Camshaft Position Sensor Circuit High Input
P0344 Camshaft Position Sensor Circuit Intermittent
P0350 Ignition Coil Primary/Secondary Circuit Malfunction
P0351 Ignition Coil "A" Primary/Secondary Circuit Malfunction
P0352 Ignition Coil "B" Primary/Secondary Circuit Malfunction
P0353 Ignition Coil "C" Primary/Secondary Circuit Malfunction
P0354 Ignition Coil "D" Primary/Secondary Circuit Malfunction
P0355 Ignition Coil "E" Primary/Secondary Circuit Malfunction
P0356 Ignition Coil "F" Primary/Secondary Circuit Malfunction
P0357 Ignition Coil "G" Primary/Secondary Circuit Malfunction
P0358 Ignition Coil "H" Primary/Secondary Circuit Malfunction
P0359 Ignition Coil "I" Primary/Secondary Circuit Malfunction
P0360 Ignition Coil "J" Primary/Secondary Circuit Malfunction
P0361 Ignition Coil "K" Primary/Secondary Circuit Malfunction
P0362 Ignition Coil "L" Primary/Secondary Circuit Malfunction
P0370 Timing Reference High Resolution Signal "A" Malfunction
P0371 Timing Reference High Resolution Signal "A" Too Many Pulses
P0372 Timing Reference High Resolution Signal "A" Too Few Pulses
P0373 Timing Reference High Resolution Signal "A" Intermittent/Erratic Pulses
P0374 Timing Reference High Resolution Signal "A" No Pulses
P0375 Timing Reference High Resolution Signal "B" Malfunction
P0376 Timing Reference High Resolution Signal "B" Too Many Pulses
P0377 Timing Reference High Resolution Signal "B" Too Few Pulses
P0378 Timing Reference High Resolution Signal "B" Intermittent/Erratic Pulses
P0379 Timing Reference High Resolution Signal "B" No Pulses
P0380 Glow Plug/Heater Circuit "A" Malfunction
P0381 Glow Plug/Heater Indicator Circuit Malfunction
P0382 Glow Plug/Heater Circuit "B" Malfunction
P0385 Crankshaft Position Sensor "B" Circuit Malfunction
P0386 Crankshaft Position Sensor "B" Circuit Range/Performance
P0387 Crankshaft Position Sensor "B" Circuit Low Input
P0388 Crankshaft Position Sensor "B" Circuit High Input
P0389 Crankshaft Position Sensor "B" Circuit Intermittent
P0400 Exhaust Gas Recirculation Flow Malfunction
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation Flow Excessive Detected
P0403 Exhaust Gas Recirculation Circuit Malfunction
P0404 Exhaust Gas Recirculation Circuit Range/Performance
P0405 Exhaust Gas Recirculation Sensor "A" Circuit Low
P0406 Exhaust Gas Recirculation Sensor "A" Circuit High
P0407 Exhaust Gas Recirculation Sensor "B" Circuit Low
P0408 Exhaust Gas Recirculation Sensor "B" Circuit High
P0410 Secondary Air Injection System Malfunction
P0411 Secondary Air Injection System Incorrect Flow Detected
P0412 Secondary Air Injection System Switching Valve "A" Circuit Malfunction
P0413 Secondary Air Injection System Switching Valve "A" Circuit Open
P0414 Secondary Air Injection System Switching Valve "A" Circuit Shorted
P0415 Secondary Air Injection System Switching Valve "B" Circuit Malfunction
P0416 Secondary Air Injection System Switching Valve "B" Circuit Open
P0417 Secondary Air Injection System Switching Valve "B" Circuit Shorted
P0418 Secondary Air Injection System Relay "A" Circuit Malfunction
P0419 Secondary Air Injection System Relay "B" Circuit Malfunction
P0420 Catalyst System Efficiency Below Threshold (Bank #1)
P0421 Warm Up Catalyst Efficiency Below Threshold (Bank #1)
P0422 Main Catalyst Efficiency Below Threshold (Bank #1)
P0423 Heated Catalyst Efficiency Below Threshold (Bank #1)
P0424 Heated Catalyst Temperature Below Threshold (Bank #1)
P0430 Catalyst System Efficiency Below Threshold (Bank #2)
P0431 Warm Up Catalyst Efficiency Below Threshold (Bank #2)
P0432 Main Catalyst Efficiency Below Threshold (Bank #2)
P0433 Heated Catalyst Efficiency Below Threshold (Bank #2)
P0434 Heated Catalyst Temperature Below Threshold (Bank #2)
P0440 Evaporative Emission Control System Malfunction
P0441 Evaporative Emission Control System Incorrect Purge Flow
P0442 Evaporative Emission Control System Leak Detected (Small Leak)
P0443 Evaporative Emission Control System Purge Control Valve Circuit Malfunction
P0444 Evaporative Emission Control System Purge Control Valve Circuit Open
P0445 Evaporative Emission Control System Purge Control Valve Circuit Shorted
P0446 Evaporative Emission Control System Vent Control Circuit Malfunction P0441 and/or P0446

0helpful
1answer

03 mazda mpv didn't pass inspection because of fault PO431?

Have the catalytic converter and your O2 sensor checked.
0helpful
2answers

Where should I find this sensor P0342?

EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up (masking the original reason for converter failure).
0helpful
1answer

What does a po430 code mean on a mercury cougar

EXHAUST RELATED ERROR CODES

There are 711 possible PO generic DTC error codes. Only 7 of the 711 codes are exhaust related.

PO401: Insufficient EGR Flow

PO402: Exhaust Gas Recirculation (EGR) Excessive Flow Detected

PO410: Secondary Air Injection System Malfunction

PO420: Catalyst System Efficiency Below Threshold (Bank 1)

PO421: Warm-Up Catalyst Efficiency Below Threshold (Bank 1)

PO430: Catalyst System Efficiency Below Threshold (Bank 2)

PO431: Warm-Up Catalyst Efficiency Below Threshold (Bank 2)

THINGS TO ASK YOURSELF OR YOUR CUSTOMER

Have there been any driveability or performance issues with the vehicle, have there been any recent repairs or tune-up work performed, if so was the check engine light reset and were the codes recorded on previous repair orders.

Do not rely on scan tool data alone. In most applications, the customer will have the check engine light reset prior to repair. If the original cause of converter failure is intermittent, only the catalyst failure code may show up
0helpful
1answer

I have 3 codes po431 po103 and po113

P0103 Mass or Volume Air Flow Circuit High Input P0113 Intake Air Temperature Circuit High Input P0431 Warm Up Catalyst Efficiency Below Threshold (Bank 2) A code P0431 may mean that one or more of the following has happened:
  • The catalytic converter is no longer functioning properly
  • An oxygen sensor is not reading (functioning) properly
  • There is an exhaust leak
A code P0113 may mean that one or more of the following has happened:
  • Internally failed IAT sensor
  • Faulty connection at IAT sensor
  • Open in IAT ground circuit or signal circuit
  • Short to voltage in IAT signal circuit or reference circuit
  • IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plugmag-glass_10x10.gif cables, etc.)
  • Faulty PCM (less likely but not impossible)
A code P0103 may mean that one or more of the following has happened:
  • The MAF may be disconnected, or a wiring connection may be bad
  • The MAF sensor may be damaged
  • The vehicle computer may be faulty (very rare)
3helpful
1answer

Getting codes PO431, PO421, PO128

2003 saturn vue, we dont have the engine size, the codes should be and are the same, po 128 means; cooling temp is out of spec, make sure the coolant is full, then replace the coolant emp sensor and make sure the connection is good, i would also replace the thermostant, this is a common code on these and most of the time its the coolant temp sensor or thermostant, ive learned to replace then both to avoid future engine lights with code po128. next we will check the code # po421, this code is that the computer sees that the cat converters are taking to long to warm up, code po 431 is also the same as po421, this code is related to the thermostant and sensor, the sensor give the computer the wrong temp readings and then the compuetr thinks the engine is hotter than it is and thinks the converters should be also hot like the motor but the coolant temp is giving a false reading, if you replace the coolant temp sensor and the thermostant and fill coolant , then reset the light and you will solve the problem, i hope this is helpful, also the sensor is located to the right of the engine if you are standing in front of the motor, heres a picture of the sensor, remember to check connector heres a pic of the connector, good luck.johnjohn2_20.jpg
7helpful
2answers

What are codes P1492, P0421 & P0431 on the 2002 Mazda Millenia?

po421 warm up catalyst efficiency below threshhold bank 1, 431 same on bank 2..
7helpful
3answers

I have a 2003 MPV with trouble code PO327 and PO431. What do these mean? Thank you.

P0327 Knock Sensor 1 Circuit Low Bank 1 or Single Sensor
P0431 Warm Up Catalyst Efficiency Below Threshold Bank 2


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