P0420 Chrysler Code - Catalyst System Efficiency Bank 1
Quick Answer
The Engine Control Module (ECM) monitors the switching frequency ratio of heated oxygen sensors 1 (front O2 sensor) and heated oxygen sensors 2 (rear O2 sensor). Common causes include Faulty Three-way Catalyst Converter Bank 1, Exhaust Tube, Intake Air Leaks. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0420 Chrysler indicates Catalyst System Efficiency Bank 1.
- Common causes
- Common causes include Faulty Three-way Catalyst Converter Bank 1, Exhaust Tube, Intake Air Leaks.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Code P0420 Chrysler Description
A three way catalyst converter (Manifold) with high oxygen storage capacity will indicate a low switching frequency of heated oxygen sensor 2. As oxygen storage capacity decreases, the heated oxygen sensor 2 switching frequency will increase.
When the frequency ratio of heated oxygen sensors 1 and 2 approaches a specified limit value, the three way catalyst malfunction is diagnosed.
What are the Possible Causes of the DTC P0420 Chrysler?
- Faulty Three-way Catalyst Converter Bank 1
- Exhaust Tube
- Intake Air Leaks
- Faulty Oxygen (O2) Sensor
- Faulty Fuel injector(s)
- Leaking Fuel Injector (s)
- Faulty Spark plugs
- Improper Ignition Timing
- Faulty Engine Control Module (ECM)
- Dirty Air Filter
How to Fix the DTC P0420 Chrysler?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
Code Tech Notes
User Submitted Video
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0420 Chrysler code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0420 Chrysler Code
1. What are the common symptoms of OBDII code P0420 in a Chrysler vehicle?
- Common symptoms include decreased fuel efficiency, a noticeable decrease in engine performance, and the illumination of the check engine light.
2. What is the primary cause of the P0420 code in a Chrysler, indicating Catalyst System Efficiency Bank 1?
- The primary cause of the P0420 code is often a failing catalytic converter, which may no longer be functioning at the required efficiency levels.
3. Can a faulty oxygen sensor trigger the P0420 code in a Chrysler?
- Yes, a malfunctioning oxygen sensor can sometimes provide inaccurate data to the engine control module, leading to the triggering of the P0420 code.
4. Are there any DIY repair tips for addressing the P0420 code in a Chrysler?
- DIY repair tips may include checking for exhaust leaks, ensuring the oxygen sensor is functioning correctly, and inspecting the catalytic converter for damage or inefficiency.
5. How critical is it to address the P0420 code promptly in a Chrysler vehicle?
- It is important to address the P0420 code promptly as ignoring it may lead to further damage to the catalytic converter and potentially result in more expensive repairs down the line.
6. Can a dirty or clogged air filter contribute to the occurrence of the P0420 code in a Chrysler?
- Yes, a dirty or clogged air filter can disrupt the air-fuel mixture ratio, potentially causing the catalytic converter to work harder and triggering the P0420 code.
7. Is it possible for a faulty spark plug to be a contributing factor to the P0420 code in a Chrysler?
- Yes, a faulty spark plug can lead to incomplete combustion, which may affect the efficiency of the catalytic converter and result in the P0420 code being triggered.
8. How can a Chrysler owner prevent the recurrence of the P0420 code in the future?
- Regular maintenance, such as timely replacement of spark plugs, air filters, and oxygen sensors, can help prevent the recurrence of the P0420 code in the future.
9. Is it safe to continue driving a Chrysler with the P0420 code illuminated?
- While it may be safe to drive in the short term, continuing to drive with the P0420 code illuminated can potentially cause further damage to the vehicle's emissions system and should be addressed promptly.
10. Can using poor-quality fuel contribute to the triggering of the P0420 code in a Chrysler?
- Yes, using poor-quality fuel with a higher sulfur content may lead to premature degradation of the catalytic converter, potentially triggering the P0420 code.
Discuss the causes and fixes for P0420 Chrysler OBDII Code
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Pacifica was running fine when light came on no misfires. Car has 100,000 miles. I changed the two o2 sensors for 35 dollars Denso brand. I reattached the battery cable.The converter has no heat marks on it and the temp of the converter after driving was 450F on the inlet and 550F on the outlet so hopefully it is working. I drove it for 20 miles and no light. Tomorrow I will take the car to work and have scan tool connected to make sure no pending codes are there and the green light is on saying it will pass emissions
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What model and year is your vehicle? are there any other driveability problems or just the engine light ON?
Some people claim that using high octane gas and/or fuel additives sometimes will fix the problem, but if it's already coming apart, there is nothing you can do.
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I didn't want to take a chance so I replaced it for 214.00 dollars and it is working fine
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Mine is 2012 t&c with 86k miles and since 23k miles when I purchased it I've always put high quality gas 91 or better.. Mine said bank one catalytic efficient below threshold
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hi, i replaced downstream sensor and everything is OK, sebring 2005 2,7 100Kmiles
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Hi i have a 2007 pt cruiser and the engine light just came on. How long can i keep driving my car without it affecting anything else?
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The P0420 means that the catalytic convert is not working properly. Continue driving the vehicle without the repair will cause the the vehicle to fail smog check and may reduce engine performance. If you don't have the smog check done and you don't feel any engine performance problems, the you can keep driving for as long as you want.
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did you replace the CAT too for $214? that's a good price! I get the code when driving steady speed 1500-1800 RPM high gear but there was a time it went off on its own. I cleared the code twice and it has come back on for the third time, but like you no performance issues or misfires.
2006 sebring 2.7LV6 170,000 km all fluids and checks normal no performance issues or misfires.
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how did you come to this conclusion? Mine only comes on randomly at my conditions I mentioned earlier.
2006 sebring 2.7LV6 170,000 km all fluids and checks normal no performance issues or misfires.
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so far I haven't noticed any fuel economy differences as I track it religiously. But the code coming on at random moments (sometimes a few days, sometimes within a day), suggests something is not right there. So figuring out if its the o2 sensors or the CAT itself.
2006 sebring 2.7LV6 170,000 km all fluids and checks normal no performance issues or misfires.
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Yes the compete system can be found at Rockauto I wanted it right away so I went to Advanced auto .com and priced matched them and got it an hour later. Advanced auto will match any on line price. The store won't you have to go to Advancedauto.com
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wow i will check that out thank you!
edit: oh shit im not sure where you found the complete emissions system for sale on advanced auto since im having trouble finding the parts.
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advancedauto.com walkerpart 54735 for 218 dollars ordorman for 347 dollars you get the manifold converter and flange. No one gives you the muffler and back pipes those are always separate
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Try the upstream O2 sensor the sensor might be getting lazy. The number of miles you have the sensors are probably not working up to specs. If you do replace them disconnect battery and let the computer learn the new sensors
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Hi, I have this very same problem with my 2008 2.7 avenger. It always comes when driving steady speed with low rpm. Did you got this problem solved?
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