P0420

[selavia]

Hey guys,
my parents 1997 528i had the CEL go on; pulled the code; was p0420. Cat running below threshold or something like that. I was told it could either be the 1st O2 Sensor of the Cat needs to be replaced. Any thoughts? I put in "Guaranteed to pass" in the fuel line because BMW of Towson told me that the computer is sensitive and carbon build up can trip that code. I was doubtful, but I figured a $6.00 fix is worth a shot. I'd hate for it to be the cat. Also any thoughts on were to get a cheap cat for that car? I don't want to put on a universal; I'd like a direct replacement.

Also, right before the light went on, I replaced the valve cover gasket. I don't think the two would be related, but I was curious.

Thanks in advance.
Sean

 

[slickbrave]

I recently had to replace both cats on my '95 540. The independent mechanic in Nashville got some from a supplier in Texas who supposedly got them from Germany. They were $500 plus each, but he said he had problems with other aftermarket cats lasting only a few months before giving another CEL. $500 is not cheap, but it's better than $1200 from the dealership.

 

[epj3]

www.autohausaz.com has the DEC cat's for a good price.