Engine Fault codes

[soapy_g]

Hi Guys,
Had a few frustrating months with my RS4 since purchasing it in the Spring, trying to get to the bottom of a full diagnostic check - so i did what any sensible person would do and got myself a Vagcom thingy

I have found the following error codes today and the engine does seem to have "dirty power" or stuttering around 2,000 rpm ( what was i doing at such a slow speed i hear you say):

3 Faults Found:
17831 - Secondary Air Injection System; Bank 1: Insufficient Flow
P1423 - 35-00 - -
17819 - Secondary Air Injection System; Bank 2: Insufficient Flow
P1411 - 35-00 - -
17866 - Exhaust Gas Temp Sensor 2 (G236): Short to Ground
P1458 - 35-10 - - - Intermittent
Readiness: 0000 0000

I had the fault codes run around a couple of months ago in a garage but the EGT one didn't show then.

I am trying to run the FATS logs, but am not an engineer, so may take me some time to work out how to do that !

As i am in Hong Kong, it is unfortunately not an option to toddle down to MRC...

Any helpful pointers would be well received.

cheers

[surfpilot]

Hey Soapy G! Nice to hear from a 'neighbor'...I am in the Philippines. I own the one and only RS4(B5) here...there are a bunch of RS4(B7)s here.

Cheers!

Manny

[neckarsulm]

EGT fault will restrict boost.
Check the wiring first and if necessary replace the EGT sensor.
There's plenty of info on EGT sensors if you have a search.
Can't advise of the first 2 codes though but again, a search may find something.
Good luck.

[soapy_g]

Thanks for the EGT tip, which i will look into further ( as well as MAF, DV's, N75 etc !) This is my first turbo car and i am really starting to get very paranoid ...
Anyway, i managed to log some blocks with VAGCOM which show boost is way down ( not getting above 1400 mbar on full throttle). 115 log is as follows ( fields are - Time stamp, rpm, engine load %, specified boost mbar, actual boost mbar) :

Group B: '115
Engine Speed Engine Load Boost Pressure Boost Pressure
TIME (G28) (specified) (actual)
STAMP /min % mbar mbar
391.42 2880 13.5 990 1020
397.76 3200 105.3 1610 1330
398.66 3520 116.5 1650 1410
399.57 3840 118 1650 1410
400.48 4160 118 1650 1420
401.42 4480 120.3 1770 1410
402.39 4800 119.5 1880 1410
403.39 5120 121.1 2000 1410
404.42 5440 117.3 2090 1400
405.49 5760 118 2090 1390
406.58 6080 119.5 1670 1400
407.70 6360 115 1700 1380
408.83 6480 42.1 990 1350


Block 120 logs from the same session ( fields are - Time stamp, rpm, specified torque, actual torque, ASR status) :


Group C: '120
Engine Speed Torque specified Engine Torque Status
TIME (G28) by ASR (actual)
STAMP /min Nm Nm
391.72 2840 599.8 0 ASR OFF
398.06 3280 599.8 282.2 ASR OFF
398.96 3600 599.8 294 ASR OFF
399.87 3920 599.8 296.9 ASR OFF
400.79 4280 599.8 288.1 ASR OFF
401.74 4560 599.8 288.1 ASR OFF
402.72 4920 599.8 288.1 ASR OFF
403.73 5240 599.8 276.4 ASR OFF
404.77 5560 599.8 276.4 ASR OFF
405.85 5880 599.8 276.4 ASR OFF
406.95 6160 599.8 264.6 ASR OFF
408.08 6440 599.8 255.8 ASR OFF
409.20 5880 599.8 0 ASR OFF


( Dont know what ASR off is ?)

I see that i didn't really do the FATS log correctly as i started to do full throttle only at 3,000 rpm. But the boost shows values well down on specified ones.

The MAF reading at the same timegot upto 207 at 6,240rpm, so that seems to be ok ?

ANyway, i don't appear much further on and am trying to get the local garage to have a look at pressure testing the system ( not exactly sure what that is though but it is in a lot of other posts - a little knowledge is a dangerous thing), followed by MAF, EGT, DV and N75 replacements before resorting to the garage suggested new turbos - Yikes !

Anybody have any thoughts about the logs above that could give further light on the error codes in the OP and that might avoid having to go for new turbos and the engine out , please ?

cheers
soapy