B5 Models Please discuss all 1996 - 2001 B5 A4 topics here...

P0431 and P0421

  #1  
Old 12-03-2012, 09:12 PM
TheCounty's Avatar
1st Gear
Thread Starter
Join Date: Sep 2012
Posts: 15
Default P0431 and P0421

Did a rear passenger O2 sensor ( 2000 quattro with 2.8) which solved several obvious Check engine codes. Was all clear until the occasional p0431 code came up which had not been evident previously. Cleared it with the reader & it was Ok for a week. Repeated same which would last a day or week, once including P0421. Not much internet solutions on these two codes except "replacing cats". As I just had an excellent e-test and light would stay out, figured it was time to fiddle. Long story short, found secondary air injection hose clip at bottom of TEE at rear of engine loose. Clip would not secure & it was likely rattling loose occationally. Wire tied the SOB up tight & all is well. Hope this pops up on "searches" & others benefit from my folly. Yes I had that clip apart to nicely route the O2 sensor installed recently but thought it was secure when reconnected. In short, suggest checking these secondary air injection lines/clips before jumping into CATs. when getting occasional P0431 or P0421 codes.
By the way, can anyone tell me the proper "trade" name for these plasic hose built in clips/connectors.
They are a pox on mankind. Never do they want to release and usually a bear to get back on. The engineer that designed ( designed??) these should have his head caved in flush with his shoulders using a 1 1/2 " wrench. (yes imperial, just seems appropriate. )
Yes I also get the fact that they are more for quick assembly during construction but that does not make it right.
Cheers
TheCounty
 

Last edited by TheCounty; 12-03-2012 at 09:15 PM. Reason: forgot words
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
brewder
B6 Models
10
11-23-2013 01:17 PM
existence1000
B6 Models
3
04-08-2013 12:47 AM
bigdadi
Audi A6
1
10-25-2010 09:55 AM
monkey323i
B6 Models
1
04-28-2008 11:05 PM
jlewis166
Audi A6
4
09-08-2007 09:06 AM


Thread Tools
Search this Thread
Quick Reply: P0431 and P0421


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.