I have a 2005 outback llbean 3.0 with 146,000 miles.
Today the check engine light came on with a blinking cruise control light.
Had the code pulled at Advance which said P0420 Catalyst system efficiency below threshold
What is the fix?
O2 sensors? up or down stream is there a way to determine? Best place to purchase and what brand? I assume down stream by the wording of the code??
Suggestions are greatly appreciated.
I did replace the pcv valve about 1000 miles but not OEM. Also I believe there are oil leaks around the valve covers that should be fixed.
Thanks in advance for your wisdom.
gerald in NC
2005 subaru outback llbean