Need a little direction on a few codes I have

[Club Cheetah]

Hi guys,

I have a 2003 Allroad with the 2.7t in it. I have a post in the allroad section, but figured there's way more traffic and expertise in here. I have a few codes I'm trying to chase down. My wife had the car for the last year or so until she got a new one. I luckily get this car back as I'm in love with it. it has 186k on it, has piggie pipes, stage 1 tune, RS4 clutch, and a 6MT.

The car runs great, aside from an oil leak that will be fixed this weekend. I have the SAI coded out per the tune, and have the valves left on the block. I'm going to swap out and replace with the delete plates if that is causing an issue.

The rear O2 sensors are also coded out per the tune, but I am getting them in the list of codes for my CEL. The codes I have are:

17965 - Charge Pressure Control
P1557 - 35-00 positive deviation

16521 - O2 sensor B1 S2
P0137 - 35-00 Signal too low

17884 - EVAP Leak detection pump
P1476 - 35-00 malfunction/insignificant vacuum

18010 - Power Supply terminal 30
P1602 35-00 voltage too low - intermittent

16514 - O2 Sensor B1 S1
P0130 - 35-00 Malfunction in Curcuit

I assume I need to start with replacing my B1 S1 sensor. Not sure about ht e rest, which is why I'm thinking about the SAI and valves. Any help would be appreciated. I'm terrible at diagnosing, but have had the motor out a couple times with no issues at all so am mechanical.

Mike

[Club Cheetah]

Oh, something I just remembered. When the turbos are just starting to kick in at 2500 or so, there is a slight shutter. I'm reading and finding that might have something to do with it.

[Corradovolksb]

For sure start with a new B1S1 as long as you don't have a wiring issue or power ground issue to the sensor. You should also replace the B1S2 while your at it that way both banks will read the same.
Pressure test the charge system and check for leaks for P1557
Make sure you have vacuum at your LDP and if you do then your pump is faulty.
Don't worry about the voltage fault. You prob had a dead battery at one point and never cleaned the faults.

Your shudder under at low rpm could be from a boost leak but that bad 02 sensor could also cause it.

[Club Cheetah]

If the rear o2 sensors are coded out, is that one even active? Or is the possibility that the rear isn't actually coded out possible since it's reading? That's part of the reason I'm so thrown off by the second sensor error.

I'll pick up a front and swap it out while looking for melted wires etc. I'm just gonna put the SAI back in and see if that helps with any of this while I'm in there.

[hoeser]

Hi guys,

I have a 2003 Allroad with the 2.7t in it. I have a post in the allroad section, but figured there's way more traffic and expertise in here. I have a few codes I'm trying to chase down. My wife had the car for the last year or so until she got a new one. I luckily get this car back as I'm in love with it. it has 186k on it, has piggie pipes, stage 1 tune, RS4 clutch, and a 6MT.

The car runs great, aside from an oil leak that will be fixed this weekend. I have the SAI coded out per the tune, and have the valves left on the block. I'm going to swap out and replace with the delete plates if that is causing an issue.

The rear O2 sensors are also coded out per the tune, but I am getting them in the list of codes for my CEL. The codes I have are:

17965 - Charge Pressure Control
P1557 - 35-00 positive deviation

16521 - O2 sensor B1 S2
P0137 - 35-00 Signal too low

17884 - EVAP Leak detection pump
P1476 - 35-00 malfunction/insignificant vacuum

18010 - Power Supply terminal 30
P1602 35-00 voltage too low - intermittent

16514 - O2 Sensor B1 S1
P0130 - 35-00 Malfunction in Curcuit

I assume I need to start with replacing my B1 S1 sensor. Not sure about ht e rest, which is why I'm thinking about the SAI and valves. Any help would be appreciated. I'm terrible at diagnosing, but have had the motor out a couple times with no issues at all so am mechanical.

Mike

16521 - Are you sure it's the O2 sensors that are coded out, or are you talking about the EGTs?
17965 - is likely a boost leak. Build a pressure tester. Also check common leak points, throttle body boot is super common.
16514 - is pre-cat passenger side O2 sensor, changed mine out in less than an hour.. very easy with an O2 sensor socket or even the crow's foot style tool.

[Club Cheetah]

I'm going to get the universal O2 sensor and swap out the precat one, get the pressure tester and look for leaks. Currently the boost feels smooth, aside from that initial hiccup when the turbos start to kick in.

I assume the O2 sensors are coded out, as that's what I paid the guy to do. I also requested to have the SAI coded out, which I'm gonna just put back in the car to fix any worry I might have with that.