P0420 / Catalytic Converter Workaround
#1
P0420 / Catalytic Converter Workaround
Have been thru three cat converters on my '05 Pac. The engine light comes on every 2 years and throws the dreaded P0420 code when the cat falls below 96% efficiency.
In my state it is allowable for a vehicle to pass emissions inspection with 1 monitor not complete. For the past three years I have used a simple I/M scanner, AutoLink #AL319, to reset the monitors and engine light. Then after about 55 miles of casually driving around town all the monitors will check in with a passing grade, leaving the Cat monitor as the sole monitor not complete. Duck into the nearest inspection station without shutting off the engine and she passes with 1 monitor not set.
All is good once again. Maybe I will bit the bullet and put another new Cat on it next year...
In my state it is allowable for a vehicle to pass emissions inspection with 1 monitor not complete. For the past three years I have used a simple I/M scanner, AutoLink #AL319, to reset the monitors and engine light. Then after about 55 miles of casually driving around town all the monitors will check in with a passing grade, leaving the Cat monitor as the sole monitor not complete. Duck into the nearest inspection station without shutting off the engine and she passes with 1 monitor not set.
All is good once again. Maybe I will bit the bullet and put another new Cat on it next year...
Last edited by djetelina; 10-23-2018 at 11:47 AM.
#2
Another work around that can be done is using a spark plug anti fouler to fool the post cat sensor. Pull the post cat sensor, get 2 spark plug anti fouler s that fit the thread, drill one out so the tip of the sensor fits thru. Reinstall sensor using both anti fouler s and you will not see the code again. Has worked for me and many others
#3
Another work around that can be done is using a spark plug anti fouler to fool the post cat sensor. Pull the post cat sensor, get 2 spark plug anti fouler s that fit the thread, drill one out so the tip of the sensor fits thru. Reinstall sensor using both anti fouler s and you will not see the code again. Has worked for me and many others
#4
Another work around that can be done is using a spark plug anti fouler to fool the post cat sensor. Pull the post cat sensor, get 2 spark plug anti fouler s that fit the thread, drill one out so the tip of the sensor fits thru. Reinstall sensor using both anti fouler s and you will not see the code again. Has worked for me and many others
Last edited by djetelina; 10-30-2018 at 04:06 PM.
#6
Hello:
Had engine light come on with code PO430. Cat. below efficiency. I am looking for spark plug anti-foulers that fit my 2005 Chrysler 300c, 5.7 hemi. Found a part number 42009 by HELP. Are these foulers universal or made to fit downstream exhaust?.
Thanls
Had engine light come on with code PO430. Cat. below efficiency. I am looking for spark plug anti-foulers that fit my 2005 Chrysler 300c, 5.7 hemi. Found a part number 42009 by HELP. Are these foulers universal or made to fit downstream exhaust?.
Thanls
#7
Rather than drilling out a spark plug anti-fouler I bought an O2 spacer for $5 on ebay. I used anti-seize compound and I did not overtighten this aluminum part.
In California all monitors need to be ready or you will fail smog for model years 2000 and later. I used an ELM237 Wifi module and the free AutoDoctor app to check ready status. I had to drive 195 miles before the catalyst monitor was ready. Then I removed the spacer and passed the smog test.
Do not leave the spacer in place for smog test! Not only will you fail visual inspection, but your vehicle will be flagged to require replacement of the converter. Assuming the smog guys are doing their job.
Removing the O2 spacer is easy on the Pacifica. If the P0402 code reappears I will reinstall the spacer and leave it there until just before my next smog test.
Update: The code returned a few miles later, so I installed a new Mopar downstream O2 sensor. Five miles later AutoDoctor says that the catalyst is now ready for inspection. Maybe I only needed a new downstream sensor the whole time.
Update 2: Yes, I needed only the new downstream sensor. It's still code-free without the spacer.
In California all monitors need to be ready or you will fail smog for model years 2000 and later. I used an ELM237 Wifi module and the free AutoDoctor app to check ready status. I had to drive 195 miles before the catalyst monitor was ready. Then I removed the spacer and passed the smog test.
Do not leave the spacer in place for smog test! Not only will you fail visual inspection, but your vehicle will be flagged to require replacement of the converter. Assuming the smog guys are doing their job.
Removing the O2 spacer is easy on the Pacifica. If the P0402 code reappears I will reinstall the spacer and leave it there until just before my next smog test.
Update: The code returned a few miles later, so I installed a new Mopar downstream O2 sensor. Five miles later AutoDoctor says that the catalyst is now ready for inspection. Maybe I only needed a new downstream sensor the whole time.
Update 2: Yes, I needed only the new downstream sensor. It's still code-free without the spacer.
Last edited by myf16; 05-28-2020 at 11:40 AM. Reason: corrected name of app to show ready status
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