When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Read and cleared engine code P0420. I drove it for a few days and the engine symbol is back on my dash. I have not read the code today, but feels like a P0420.
There are a few possibilities and I am hoping to narrow it down if possible. Is it an O2 sensor or has someone had other troubles after getting this code?
Unless you have a scanner that can monitor the O2 sensors, I would replace the sensors. The ECM monitors front and rear sensors, and compares readings to determine if the converter is doing its job. Does the vehicle have, or ever had, a misfire problem? If not repaired quickly, the converter can be damaged and cause a cat efficiency problem that may not show up for some time