EdyJun

After looking at the logs I am very confused. I first thought my car was in some kind of "Limp Mode" but no CEL.

Found this when I got back home.
1 Fault Found:

17965 - Charge Pressure Control: Positive Deviation

P1557 - 35-00 - -

Then I searched the archives and found this

"17965? Usually means actual boost is not meeting the expected (often a boost leak).
It sounds backwards, but from what I've seen, positive deviation = underboosting, negative deviation = overboosting."

Posted By DarinS4Turbo

Now I have 2 questions?
1. Is this correct does it look like I have a boost leak?
2. Do I have bad O2 sensors (4 of them)? (Both primary O2s were changed less than 1 year ago)


Conditions:

74 deg
IC temp was between 40-50 deg Celsius (104-122 F)

GIAC X only
Reset ECU and then drove around for 1 hour (~25 miles).



LOGS - Stock timing

<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/2-3-115.htm">Block 2-3-115</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/2-31-115.htm">Block 2-31-115</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/3-31-115.htm">Block 3-31-115</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/20-21.htm">Block 20-211</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/20-21-2.htm">Block 20-21 #2</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/20-21-3.htm">Block 20-21 #3</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(0)/20-21-4.htm">Block 20-21 #4</a>




LOGS - +2.25 timing

<a href="http://homepage.mac.com/edyjun1/S4/web-timing(2.25)/31-20-21.htm">Block 31-20-21</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(2.25)/31-20-21-2.htm">Block 31-20-21 #2</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(2.25)/31-20-21-3.htm">Block 31-20-21 #3</a>
<a href="http://homepage.mac.com/edyjun1/S4/web-timing(2.25)/115-20-21.htm">Block 115-20-21</a>

<a href="http://homepage.mac.com/edyjun1/S4/web-timing(2.25)/115-diffrent-gears.htm">Diffrent Gears 115</a>




Some times the boost goes past 5 psi but mostly it stays below. IF this is some kind of Limp Mode how come request is still high?


Bock 032 - after getting home.

<img src="http://homepage.mac.com/edyjun1/S4/32.jpg">

Thank you
Edy

AudiS4guy - NorCal

once you turn off the ignition your boost should go back to normal. However, once you get on it again it'll go back into limp as I can see from your logs. It wouldn't hurt to log 34 and 43 (EGT's) You might also want to check your n75 valve as I just worked on a car with a bad one and had the same symptoms as you.

EdyJun

1 Fault Found:

17965 - Charge Pressure Control: Positive Deviation

P1557 - 35-00 - -

only one found.

Are the O2s bad?

How do i get the Dealer to fix the O2 and N75 if they are bad.

Thank you for you response.

p.s
I will log 34 and 43 when i can.

nyet

limp mode will show very low req.

PSmalls::DoggieStyle

Seems like a *major* boost leak to me. Stop messing with lemmiwinks and find the problem.

EdyJun

Thank you all for helping me out. I will not be driving my S4 until I can the parts or get the dealer to fix it.

BUT do I still have bad O2 sensor(s) or not?

PSmalls::DoggieStyle

Do some more logging after fixing your leak.

EdyJun

So O2 sensors are ok or do you mean u don't think its just the TBB?

PSmalls::DoggieStyle

I meant 02 sensors seem okay. Log again when you fix the TBB or whatever is leaking.

EdyJun

Ok thanx alot for the help.