Q: Code P0420 shows on the dash of my 2005 Acura MDX

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I have a 2005 MDX with check engine light on, code p0420. Did a smog test on it, failed reading bank 1 sensor 2 was putting off bad readings. Replaced that o2 sensor to see if that would fix it, didn't work. What should I do? Get the new converter? If so, can you tell me exactly which converter it is? Maybe a part number?

My car has 135000 miles.
My car has an automatic transmission.

Acura did have a tech bulletin released in September 2011 regarding fault P0420 and a possible software update that may rectify this situation. You can try contacting your local Acura dealer service department or Acura Customer service to see if this software update was ever performed to your vehicle and if it would still apply even with the current mileage. Odds are that if replacing Sensor 2 did not clear the P0420 fault and this software update was either already done or no longer is applicable due to the mileage, the converter may very well have to be replaced.

You can try to paste this url into your browser to see/print a copy. Maybe it will help you. http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM427428/CSC-10042831-9485.pdf

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