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Hi All,

I was wondering whether anybody out there could help decipher the cause/relevance/significance of the following codes that the S4 is now coughing up!!?


16815 Warm up catalyst; bank 2
P0431 - 001 - Efficiency below threshold - Intermittent - MIL O

16805 Warm up catalyst; bank 1
P0421 - 001 - Efficiency below threshold - Intermittent

18017 Crash Shut-Down Actuated
P1601 - 001 -

They have been reset, but the first two also appeared about 6 weeks ago, were reset then but had returned.
The car has no precats, second lambdas now behind main (sports) cats, and to the best of my knowledge I have not been involved in a crash !!

Thanks in advance to anyone who can shed some light!

Steve

smyffie wrote:Hi All,

I was wondering whether anybody out there could help decipher the cause/relevance/significance of the following codes that the S4 is now coughing up!!?

16815 Warm up catalyst; bank 2
P0431 - 001 - Efficiency below threshold - Intermittent - MIL O

16805 Warm up catalyst; bank 1
P0421 - 001 - Efficiency below threshold - Intermittent

How long the sport cats been fitted?

18017 Crash Shut-Down Actuated
P1601 - 001 -

That's IIRC the airbag system telling the engine ECU that there's been a crash and shut down immediately.
If there's no timestamp then it could be an old code. Have you had the car from new?

Sports cats fitted nearly two years ago. Owned the car nearly four years, third owner, but have VAGCOMed it in the past and that fault never showed up

sports cats could be on their way out - they do degrade over time and as sport cats cut it quite close to begin with it wouldn't take much.

i have the same code about efficiency below threshold, it clears but then returns eery now and then, ive done alot of searching and finially got an answer from JHM who said the cat was dead, so ive ordered a new exhaust