P0420 Code

[blageo23]

What is it. We went to checkers and thats what came on on the little thingy but the didnt have the info on it. Car: 1998 BMW 323IS. What is it and whats the fix? any help will help.
Thanks,
Mike

[JET]

The 420 code means the bong is low on water :eek:

[StealthGST]

Replace Schwag immediately

[Shane@DBPerformance]

P0420 Low nugz efficiency - replace with fresh bowl



Or just search google for the real answer.

[LightningGSX]

I believe the code means the bank 1 catalyst efficiency is below the threshold.I'd check the bank 1 secondary o2 sensor, primary o2 sensor, and the cat itself in that order.It's more than likely the bank 1 secondary(post cat) o2 sensor

[santa]

powertrains is what the P means 0 means SAE controlled and the 4 means auxilary emissions controls and the rest well my best knowledge is poossible catalyst monitor code...

[LightningGSX]

http://www.dsmstyle.com/forums/showthread.php?t=7321