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p0421
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Threads Tagged with
p0421
Thread / Thread Starter
Last Post
Replies
Views
Forum
Possible Solution for Catalytic Converter fault codes - P0421 & P0431
(
1
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Last Page
)
A84Nate
on 12-09-2010
10-13-2016
02:08 PM
by
maxiwoofus
30
148,232
A4 (B6 Platform) Discussion
Code P0421 was NOT catalytic converter
dpeverhart
on 02-24-2010
10-07-2014
11:30 AM
by
Prospeeder
6
25,750
A4 (B5 Platform) Discussion
fixed 16805 P0421 with O2 extender
johnkk
on 09-22-2013
09-22-2013
06:46 AM
by
johnkk
0
2,485
A6 / S6 (C5 Platform) Discussion
P0421 already replaced cat
Kombi03
on 02-05-2013
02-14-2013
03:58 PM
by
2000_A6_2.8_Avant
4
3,332
A6 / S6 (C5 Platform) Discussion
Allroad Won't Start, Please Help
(
1
2
)
mmasner
on 02-06-2013
02-12-2013
06:22 PM
by
mmasner
17
38,127
Audi allroad
P0421 and misfires 04 A4 3.0
blueskymine
on 09-14-2012
09-20-2012
01:57 PM
by
ct_esq
2
3,693
A4 (B6 Platform) Discussion
P0421 and Gas -- anyone had similar story?
a4avant99
on 05-25-2012
05-25-2012
10:56 AM
by
2.7Lturbo
7
2,191
A6 / S6 (C5 Platform) Discussion
2001 S4, CEL/Catalytic Issues
yakavish
on 03-21-2012
04-09-2012
03:16 PM
by
yakavish
9
4,324
S4 / RS4 (B5 Platform) Discussion
Trouble getting through emissions testing
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1
2
3
)
M4NB00B5
on 01-24-2012
01-26-2012
05:50 PM
by
jcman
20
5,955
A6 / S6 (C5 Platform) Discussion
Fault codes:P0431,P0421,P1603-intermittent?
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1
2
3
)
tmaslar
on 01-20-2007
11-21-2011
11:52 AM
by
02ALLROAD02
24
47,108
VAG-COM Discussion
P0421, spark plug replaced, then ABS and ESP
a4avant99
on 11-06-2011
11-11-2011
01:48 PM
by
a4avant99
8
5,073
A6 / S6 (C5 Platform) Discussion
Codes P0421 and P0431
ShadowF
on 08-13-2011
08-13-2011
03:31 PM
by
ShadowF
0
4,911
A4 (B6 Platform) Discussion
Catalytic Converter - Cheap Fix from Dealer
2002 allroad
on 04-21-2011
07-08-2011
10:33 AM
by
O2Allroad
7
19,975
2.7T V6 Discussion
APR fix vrs TSB fix at audi
(
1
2
)
mikester2008
on 06-10-2011
06-14-2011
05:42 AM
by
thejulex
10
1,977
Audi allroad
Miss while at constant speed
(
1
2
3
)
normohl
on 05-09-2011
05-15-2011
05:54 PM
by
EuroXS4
28
4,032
S4 / RS4 (B5 Platform) Discussion
p0421, yay (specific question)
(
1
2
)
DZA
on 03-21-2008
04-09-2011
07:59 PM
by
theugly02
12
2,828
A4 (B6 Platform) Discussion
catalytic code
host23age
on 11-19-2010
03-23-2011
01:56 PM
by
ryan_qttro
3
3,347
30v V6 Discussion
B6 A4 or D2 A8?
(
1
2
3
)
A84Nate
on 10-29-2010
11-19-2010
07:06 PM
by
A84Nate
25
3,296
A4 (B6 Platform) Discussion
P0421 and other MILs
2000_A6_2.8_Avant
on 11-19-2010
11-19-2010
04:54 PM
by
2000_A6_2.8_Avant
0
1,501
A6 / S6 (C5 Platform) Discussion
Codes??
jrc922
on 10-26-2010
10-28-2010
10:25 AM
by
jrc922
5
1,947
S4 / RS4 (B5 Platform) Discussion
2002 Audi A6 Quattro Error Code Help
l_smith
on 08-04-2010
08-06-2010
11:29 AM
by
Dana @ Ross-Tech
3
3,553
VAG-COM Discussion
Catalytic Converter Opinions - Please Weigh In
(
1
2
3
)
ilsaccente
on 05-25-2010
05-28-2010
04:42 AM
by
ilsaccente
23
5,291
A6 / S6 (C5 Platform) Discussion
P0421 May Just Be O2 Sensors
tecoya
on 05-12-2010
05-14-2010
10:33 AM
by
Pete@ECSTuning
4
2,092
A4 (B6 Platform) Discussion
P0421 - Cat code
greenquattro
on 05-01-2010
05-01-2010
06:34 PM
by
VONBOTTLE
1
2,354
A6 / S6 (C5 Platform) Discussion
Pre or Primary Catalytic Converter Question
conall
on 03-22-2010
03-24-2010
05:52 PM
by
conall
1
1,272
S4 / RS4 (B5 Platform) Discussion
vag-com code on my 02
PaJames
on 02-26-2010
03-01-2010
04:07 PM
by
PaJames
7
6,342
A6 / S6 (C5 Platform) Discussion
any way to tell if it has piggie pipes?
ucf_motorcycle
on 02-15-2010
02-16-2010
04:44 AM
by
SloopJohnB@mac.com
3
846
A6 / S6 (C5 Platform) Discussion
Need some advice on a sell vs. save decision
KneeDeep
on 01-06-2010
02-13-2010
12:45 PM
by
01A6Turbo
8
1,446
S4 / RS4 (B5 Platform) Discussion
New to A6 2.7t Few questions
Johann2.7t
on 02-05-2010
02-05-2010
06:18 PM
by
VONBOTTLE
3
1,466
A6 / S6 (C5 Platform) Discussion
Help with codes for 01 A6 2.7
tjscanlon
on 12-29-2005
01-27-2010
05:14 PM
by
leeststorm
5
1,647
A6 / S6 (C5 Platform) Discussion
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