S3 BAM - Boost Delivery Issue (LOGGING DONE - RESULTS INSIDE)

ShaunS3

Yorkshire & Humber Rep.
Regional Rep
VCDS Map User
Hi guys,

Yes, here is another thread about boost issues on an S3 8L. Cut the story short, i have done some logging and would like someone to take a look and see if they can see anything that is causing the issue.

First of all, vehicle spec:

2002 S3 225 BAM

Stage 1 Custom Code Map
Relentless V3 tubular manifold
3'' DP with 200 Cell sports cat
Miltek non-resonated cat back
AH Fabs V2 FMIC
B5 80mm TIP w/billet adapter
S2000 filter
PCV bypass w/oil catch can
Recent OEM diverter valve
Recent brand new MAF unit and connecting plug
N249 bypass
*Recent interim service, including plugs (issue was present before)
Map has been on many years and even with recent mods after map, this issue has only just come to light.


Right, here is the issue/cause for concern:

Pulsating/wavey boost delivery
Boosting to circa 20psi (cheap boost gauge was leaking heavily at the time so poss more boost pressure)
Fuel smells rich on idle, especially when cooling down from hard drive.
Airflow sounds very loud in TIP area, and deep induction rumble in low revs (lag range)
Traction Control light appears after 3rd gear between 5000rpm and 6000rpm, will not turn off (this generates MAF code below).

Fault codes present:

P0103 - MAF Sensor - Signal too high (intermittent)
P0420 - Catalyst System Bank 1 - Efficiency below threshold (intermittent)

Here are my logs:

Groups - 001 / 002 / 115

Run 1 (No fault codes present - T/C light OFF)

1.jpg

Run 2 (MAF Signal to high code present - T/C light ON)

2.jpg


Groups - 001 / 031 / 118

Run 1 (No fault codes present - T/C light OFF)

3.jpg

Run 2 (MAF Signal to high code present - T/C light ON)

4.jpg


Groups - 003 / 020 / 118

Run 1 (No fault codes present - T/C light OFF)

5.jpg

Run 2 (MAF Signal to high code present - T/C light ON)

6.jpg


Can anyone shed some light on my issues, using these logs?

Thanks in advance :)

Shaun.
 

badger5

www.badger5.co.uk
Site Sponsor
a couple of things

boost control is'nt.. shoots way past requested
Fueling is having to add a lot of fuel to try and meet the request... 20% is not a healthy number for it to have to add.

suggests under reading maf and or weak fuel pump.. (low pressure under boost)

maf too high is map/over boost level its doing.


Mods listed exceed your map
 

Gops

Badger 5 Edition
VCDS Map User
Change your pump. Mine was doing this just at the last few days then I changed it. Stage 2 time for you!
 

ShaunS3

Yorkshire & Humber Rep.
Regional Rep
VCDS Map User
Are my mods causing the issue aswell as weak fuel pump?

Would a new fpr and bigger injectors also be recommended?
 
Last edited:

ShaunS3

Yorkshire & Humber Rep.
Regional Rep
VCDS Map User
Progress:

New maf tested, no change.
New n75 fitted, no change.
Smoke test - no leaks.

Next is to purchase and fit new fuel pump, fpr and bigger injectors then straight in for map.

My issue is believe to be because my mods are allowing better flow which is exceeding the map parameters so a map should sort it.

Fueling upgrades are more surrounding it being mapped safely without any weak fuel delivery.

Hope this helps?
 
Top