MY CEL light comes on for a bit, then goes off. I am getting these codes on my truck:
Po441 says: evaporative emission system incorrect purge flow
P0420 says: Catalyst system efficiency below threshold bank 1
They seem to clear themselves after a few days, then they return in a month or so. Does anybody have guidance as to where to begin looking to remedy this? I've got 140K mikes on her & I DO NOT wish to replace the cats on this $$$. Besides, I am not sure the codes would clear themselves if the cats were truly bad.
Thanks in advance for your helpful input!
Po441 says: evaporative emission system incorrect purge flow
P0420 says: Catalyst system efficiency below threshold bank 1
They seem to clear themselves after a few days, then they return in a month or so. Does anybody have guidance as to where to begin looking to remedy this? I've got 140K mikes on her & I DO NOT wish to replace the cats on this $$$. Besides, I am not sure the codes would clear themselves if the cats were truly bad.
Thanks in advance for your helpful input!