Hy, I got a PAC 06 3.5 check engine light comes on and go off after a couple a days check the system with a scanner and I get code P0420 (Catalyst System Efficiency Below Threshold Bank 1)

Any suggestions? The place I took the car to check told me I need to replace catalytic converter they want to charge over $500.
I guess my question is if this code is related to the catalytic converter or is an O2 sensor bad?

thanks.

 

replace the converters.

 

thanks for the response I will look forward to do that

 

Ya know I am loathe to dispute the advice of a pro...but as a fellow home mech with a scanner, ya might swap the bank 1 and 2 downstream sensors and see if the problem follows the sensor or sticks with the CAT. I am fortunate to live in a non-emission test county so I would personally not be replacing a CAT without further issue. I have driven a vehicle with a clogged CAT - from a friends home to the shop - and it isn't pretty, so there is definitely a time and place for the job to be done.

Best of luck.

 

Symptom:
P0420-CATALYTIC 1/1 EFFICIENCY
When Monitored and Set Condition:
P0420-CATALYTIC 1/1 EFFICIENCY
When Monitored: Engine Run time greater than 90 seconds. Engine Coolant greater than
70°C (158°F) Vehicle speed greater than 20 MPH and less than 55 MPH. Engine Speed
greater than 1216 RPM and less than 1952 RPM.
Set Condition: As catalyst efficiency deteriorates, the switch rate of the downstream O2
sensor approaches that of the upstream O2 sensor. If at any point during the test the
switch ratio reaches a predetermined value a counter is incremented by one. One Trip
Fault.
POSSIBLE CAUSES
GOOD TRIP EQUAL TO ZERO
VISUALLY INSPECT CATALYTIC CONVERTER
EXHAUST LEAK
ENGINE MECHANICAL CONDITION
CATALYTIC CONVERTER

 

I have the same code and my mechanic friend tested the O2 sensors and they were fine.
I have been waiting until it gets closer for inspection time to buy a $500+ cat.

 

I had this problem and everyone told me to replace the converter it didn't make sense especially when the vehicle only had 45K miles on it at the time. And the O2 sensors tested good. I got under the vehicle one day and found the wiring harness that leads to the O2 sensor was pulled and damaged. I redid the wiring and the code went away. Cost? A roll of electrical tape and my time.

 

Hi,
I have 2006 Pacifica with 55k miles on it. Check engine light came on few days ago. Autozone read the code and it turn out to be a P0420.

My question is, do I have to get a Chrysler Catalytic converter or can I get an after market part? Are those Autozone brand (Magnaflow?) catalytic converters any good?

And is it worth to pay a shop to check all the wires leading to & from the Catalytic converter to make sure nothing else is broken?

Thanks.

 

Alright, two days after the check engine light came on (P0420 error code), the ABS light started coming on intermittently. I understand that ABS light has something to do with speed sensors in wheels.

But I am wondering if error code P0420 and ABS light coming on in quick succession, there may be a common malfunction causing both of these problem. Can a lose wire or a problem in certain electrical component cause both of these errors?

Thanks.

 

we have an '05 that had an 0420 code. I took it in to be sure it was the catalytic convertor for sure. The tech said it is was possible that some raw fuel got on one of the 02 sensors. He said the everything checked fine. The code is cleared. As far as the ABs, if you do take it in to be checked, they can also tell you which speed sensor is bad. I just replaced one one the rear. $30 part from rockauto.com