16815: Warm up catalyst bank 2, eff below threshold (sporadic)

[Slow4]

I googled and searched. Came up with these 3 results.

1. Exhaust leak
2. Bad catalyct converter
3. Bad O2 sensors


* How do I know which of the three is bad?
* If bad O2, how do I know which of the O2 sensors do I replace? Theres like 3 isnt there?
* If exhaust leak, how do I fix? (New exhaust system?)
* If bad CC, how do I fix? (Again, new exhaust system?)

[mholme]

I googled and searched. Came up with these 3 results.

1. Exhaust leak
2. Bad catalyct converter
3. Bad O2 sensors


* How do I know which of the three is bad?
* If bad O2, how do I know which of the O2 sensors do I replace? Theres like 3 isnt there?
* If exhaust leak, how do I fix? (New exhaust system?)
* If bad CC, how do I fix? (Again, new exhaust system?)

Bank 2 is driver side. Mine was fixed by changing the primary(upstream) sensor, even though the rears(secondary) generate the actual code, they take a reading from the two. You need a VAG-COM to log them and see which ones are out of spec.

[Slow4]

Bank 2 is driver side. Mine was fixed by changing the primary(upstream) sensor, even though the rears(secondary) generate the actual code, they take a reading from the two. You need a VAG-COM to log them and see which ones are out of spec.

I bought that VAG-TOOL/PALM thing through JayC on here. I utilized that to figure out the code...

but like you said, Bank 2 is driver side, meaning that I should replace the front O2 sensor on my side, yes?

[mholme]

I bought that VAG-TOOL/PALM thing through JayC on here. I utilized that to figure out the code...

but like you said, Bank 2 is driver side, meaning that I should replace the front O2 sensor on my side, yes?

You still need to log the sensors. One of them may be out of spec causing the code to be thrown. In my case, it was the primary that was at fault. Your mileage may vary..

[espo4442]

Yeah it's def your diver's 02's like mholme said logg your o2's and see what's going on. I have this code come up every once in awhile , but thats apparently due to the GIAC chip i have that is coded for cat delete? who knows if thats true thats just what I was told.

[tike0rz]

Subscribed because I've had a CEL for this code for a while. I've heard it was O2 sensors or cats. Most likely O2s though.

[AudiSportB5S4]

i had this code, below threshold, but thats because i have straight pipes with no cats LOL.

[highPSI-S4]

I've had this code for awhile. it was my front driver side o2. It also caused the car to throw a bunch of other codes.

Monday,19,May,2008,10:22:49:58049
VAG-COM Version: Release 704.1
Address 01: Engine
Control Module Part Number: 8D0 907 551 M
Component and/or Version: 2.7l V6/5VT G01 0002
Software Coding: 06711
Work Shop Code: WSC 88811
5 Faults Found:
17521 - Oxygen (Lambda) Sensor; B1 S1: Internal Resistance too High
P1113 - 35-10 - - - Intermittent
16815 - Warm Up Catalyst; Bank 2: Efficiency Below Threshold
P0431 - 35-00 - -
17965 - Charge Pressure Control: Positive Deviation
P1557 - 35-10 - - - Intermittent
16805 - Warm Up Catalyst; Bank 1: Efficiency Below Threshold
P0421 - 35-00 - -
18058 - Powertrain Data Bus: Missing Message from Instrument Cluster
P1650 - 35-00 - -
Readiness: 0000 0000


The other o2 sensors were good. once i replaced the primary o2 no more codes.

[tike0rz]

i had this code, below threshold, but thats because i have straight pipes with no cats LOL.

Same...does this mean I need to disable the code from being thrown?

[highPSI-S4]

Same...does this mean I need to disable the code from being thrown?

Do you have defoulers?

when i did run test pipes i had the vast defoulers and never had a problem. my only issue was emissions so know i have highflow cats.

[Allaidback]

i had this code, below threshold, but thats because i have straight pipes with no cats LOL.

I have the same issue...had did you resolve it? I bought the vast celeliminators...couldn't really get them to fit, but was told you can trim them down?

[casawhites4]

i got the vast celimnators...and they worked just perfect...had induktion trim them down some and boom i was perfect...just go that route for now.

[Slow4]

You still need to log the sensors. One of them may be out of spec causing the code to be thrown. In my case, it was the primary that was at fault. Your mileage may vary..

Noted.

Crash course on how to log the sensors?

My VAG-TOOL program has a program that logs something, is that what you gents are talking about? I guess I'll "log" them and post them...

[Evilevo]

Noted.

Crash course on how to log the sensors?

My VAG-TOOL program has a program that logs something, is that what you gents are talking about? I guess I'll "log" them and post them...

Agreed, Know how to log them, but what values will be "in spec" and what wont?

[Jayco88]

I had the same issue. I wasn't sure if it was the cat or o2 sensors. But then I did piggies and flashed my ecu with the APR stage II (which supposedly ignores rear o2's) and my problems were gone. I guess my rear o2 sensor was a little goofy.

[Allaidback]

I have GIAC stage 3 programming, but I want the o2's coded out...so what are my options and how much? Do I have to ship the ecu off or can I just find a local shop?

[Allaidback]

no luck with the vast celeliminators...couldn't get them to fit. Couldn't I just use spark plug de foulers? If I want to get it coded out in the ecu how would I do that?

[mholme]

no luck with the vast celeliminators...couldn't get them to fit. Couldn't I just use spark plug de foulers? If I want to get it coded out in the ecu how would I do that?

Yes you can. I'm running non-foulers on piggies. I thought APR stage 2+ code was the only software that eliminated the rear O2 readings.

[S4shpion]

Vast can code out the o2 readings. Contact The_Jerbel (distrubuter of Vast) and he can hook you up. I have the same problems codes were there before i got piggies and they still there after. I didnt use the celiminators, i was just going to get a semi custom tune from The_Jerbel with the o2's coded out as well as my SAP system.

[blister83]

Bank 2 is driver side. Mine was fixed by changing the primary(upstream) sensor, even though the rears(secondary) generate the actual code, they take a reading from the two. You need a VAG-COM to log them and see which ones are out of spec.

How do you log the sensors with the VAG-COM cable?