Yet another CEL

B6/7 S4/RS4
#1

Got a CEL the other day scanned and got this:

16536 - Oxygen (Lambda) Sensor B2 S1
P0152 - 001 Signal too high

Figured the sensor was dead so I ordered a new one. Found that the wires were melted together from the headers. Replaced the sensor after lengthening them. About 30 minutes into my drive I get another CEL. This time I got this:

18686 - Oxygen (Lambda) Sensor B2 S1: Negative Lead: Open Circuit
P2254 - 004 - No signal/communication

I’m guessing one of the wires probably came loose at the butt connector? I’ll probably just pull the sensor and solder them tomorrow to be safe. Any insight would be much appreciated as I couldn’t find shit from Googling the code. Another question would be, is the other sensor garbage, or should I rewire it and hold onto it until I need a new one again? The sensor is less than a year old and has maybe 200 miles on it.

#2

You would have to test the other sensor to see if its still ok. Too much feedback can kill the actual sensor itself. Also make sure to always solder the wires when lengthing or even fixing 02s. If the 02 wires ground out on eachother it can destroy your ECU. Your ECU drives the power to the 02s.

As for your code it technically should be a broken wire issues. You can also test this with a quality voltage tester.

#3

Thanks Justin!

#4

With the V1 headers I had to wrap the front O2s with heat shielding because my butt connectors kept melting together from being near the exhaust and the transmission. Especially when I was driving hard for long periods of time like on a road course.

I don’t solder because Audi wouldn’t pay for a wiring repair like that. But I would suspect that you would run into the same issue.

#5

I actually did use 2000* sheathing but apparently it wasn’t enough when they were up against the headers.

https://www.amazon.com/gp/aw/d/B00029KC34/ref=ya_aw_od_pi?ie=UTF8&psc=1

http://uploads.tapatalk-cdn.com/20160711/fe022f4fcd85527c7da2785f46dae008.png

http://uploads.tapatalk-cdn.com/20160711/ed88c07cbd971b945df88777a9e17f46.jpg

Ended up soldering them yesterday and the code is gone now.