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p0421
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Threads Tagged with
p0421
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Forum
Another P0421 code... Audi S5 2011 V8 4.2L
Audi.S5.2011.V8
on Oct 12, 2022
Oct 12, 2022
05:49 PM
by
Audi.S5.2011.V8
0
1,570
S5
Warm Up Catalyst Efficiency P0421, P0431
Euge82
on Mar 15, 2013
Sep 16, 2014
10:10 AM
by
ppgoal
6
25,370
Audi A6
Warm-Up Catalyst Below Threshold (PO421/31)
(
1
2
)
Spotty
on Feb 8, 2010
Mar 25, 2014
09:53 PM
by
mcgregor32000
17
62,082
B6 Models
Code #P0421. Please help.
(
1
2
3
)
john@astigracing.com
on Dec 23, 2009
Jan 14, 2014
09:10 AM
by
cwilson
24
22,740
B6 Models
P0421 & P0431 for years...
(
1
2
)
brewder
on Aug 13, 2013
Nov 23, 2013
01:17 PM
by
brewder
10
22,160
B6 Models
Transmission/Tiptronic FAIL-SAFE or BACKUP MODES
(
1
2
3
...
Last Page
)
soinclined
on Aug 24, 2004
Aug 9, 2013
05:54 PM
by
arielista
31
52,587
Audi A4
Vacuum Leak? codes p0306, p0421, p1177
nismo350z_burak_tx
on Aug 6, 2013
Aug 7, 2013
09:54 AM
by
twopedalwarrior
1
2,514
Audi A6
DTC codes P0421/P0431, needs new cats!
existence1000
on Apr 6, 2013
Apr 8, 2013
12:47 AM
by
existence1000
3
11,226
B6 Models
01 S4 - P0421, P1127, P1129 - Need Help!
titanko
on Jun 22, 2010
Jan 25, 2013
08:45 AM
by
titanko
8
17,288
S Car Model Line
P0431 and P0421
TheCounty
on Dec 3, 2012
Dec 3, 2012
09:12 PM
by
TheCounty
0
11,322
B5 Models
P0421....Take a look PLEASE!!!
2003audiA4avant
on Jul 10, 2012
Jul 10, 2012
04:00 PM
by
2003audiA4avant
1
4,858
Audi A4
02 sensor location on 3.0
(
1
2
)
simsaudi3.0
on Feb 2, 2008
May 17, 2012
09:44 AM
by
jlbpower
13
54,294
B6 Models
2002 A4 3.0 Quattro DTC P0421/P0431
AnthonyVas79
on Mar 17, 2012
Apr 8, 2012
11:48 PM
by
aquariumjunky
2
8,465
B6 Models
S4 2.7t p1131
tannercortes
on Mar 30, 2012
Mar 30, 2012
09:54 PM
by
tannercortes
8
12,516
B5 Models
Engine and ESP lights on (P0102, P0172, P0420, P0421)
romar1086
on Aug 29, 2011
Jan 3, 2012
06:51 PM
by
20090401
1
6,614
B6 Models
CEL: Code P0421
(
1
2
3
...
Last Page
)
saintforlife
on Jul 24, 2007
Oct 26, 2011
08:57 PM
by
igortiger
61
79,793
Audi A6
2001 Allroad shuddering p0304 code
Zeeborg
on Jun 18, 2011
Jul 14, 2011
09:33 PM
by
carbonhornet
5
5,206
Allroad Model Line
need code advice PLEASE!
mr_A6
on May 31, 2011
Jun 1, 2011
08:35 AM
by
padog
2
1,281
Audi A6
help p0421 cat code what to do?
ratherb1
on May 3, 2011
May 3, 2011
11:31 AM
by
ratherb1
0
5,374
Audi A6
'00 B5 S4 with P0421
the24thletter
on Apr 16, 2011
Apr 16, 2011
02:08 PM
by
the24thletter
0
4,117
S Car Model Line
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