Like the title says, the error code is consistently coming up (tho i clear it) as P0420.
I ignored it for about 5 or 6 months now.
But about a month ago i started hearing the rattle - it is not a heat shield.
Had it up on a houst by a local mechanic and the rattle (hitting it by hand) is coming from the front driver catalytic converter - as if chuncks of metal or coins are loose in there.
But no rattle on the front passenger cat.
Should i replace both?
Just so you know about 3 years ago i replaced all 4 cats - they were super cheap!!!