JB1/JB4,but not limited to - Oxygen (Lambda) Sensor Signal B1 S2

Hi All

I have been getting the check engine light since I added the JB1 and still getting when I upgraded to the JB4 (map1, 2 and 6 same results) . I have a CATted (200 cels) downpipe installed. I Have tried with 02 extender, mini cat and without and I'm still getting the check engine light. When I drive normal, or my wife drives my car , it disappears. (So it's not a faulty 02 sensor.)

The first thing I want to know is this normal with the tune or is there something I can do to rectify the check engine light permanently?

The errors I'm getting are the following:

18933 - Oxygen (Lambda) Sensor Signal B1 S2
P2270 00 [237] - too Lean
MIL ON - Confirmed - Tested Since Memory Clear

Car is an Audi S3 Sedan (2016)

The 42dd spacer have got some good reviews. Ive a hjs euro6 class downpipe without issues.. the reason you get the cel is insufficient cat.

Read this thread

http://www.golfmk7.com/forums/showthread.php?t=22405

Interesting: "Hg motorsport in Germany told me that the replacement of the gasket should be done every time you remove the downpipe to avoid any error codes."

Definitely need to check this. A shop did this for me, don't know if the DP came with a gasket or if they even replaced it.

But this would explain why it's always running to "lean" ..

edit: had a look on the turbo/downpipe mounting and can't see a gasket (Don't know if it should be visible or not). Since I have checked everything else in the past from wiring and sensor spacers, I went ahead and ordered a new gasket (part no: 5Q0253115B - $20 ). Will update to tell about the outcome.

Ok so replaced the gasket and cleared the codes, will see what happens.

The new gasket is about 1-2mm thicker than the old, which on a gasket is a big difference.
The downpipe bracket was easy to loosen up, meaning like one hand comfortable, no strain what so ever. Don't think that's the way it was supposed to be. I have however fastened it pretty good this time.

So far still going strong with no check engine light.

Happy for you... Hoping it was just this gasket between turbo and downpipe.