Found a cheap pre-cat O2 SENSOR ( Cheaper than 06A 906 262 Q )
Needed a new o2 sensor so I looked around a bit. The 06A906262Q part is about $100 and has a very long wire (maybe 2 feet longer than the TT225's original pre-cat o2 wire).
This alternative sensor (Bosch 16109 / Audi 06A 906 262 F ) is considerabily cheaper ($60 from Amazon with free shipping, link below) and only about 2 inches longer than the original 225 sensor. The only downsides is that you have to cut off a little bump on the connector which only take a few seconds with a razor. Oh, and the connector is orange/brown instead of black, but who cares...
I Checked block 30 after installing the sensor and voila: 111. Also checked fuel trims on block 32 and everything is within spec. the sensor works great!
Audi part# 06A906262F Bosch part# 16109
Notice the protrusion circled in red. It can be removed within seconds with a common razor...
SAME o2 sensor as the post-cat, but not sure if it is long enough. Can anyone measure the wire.....
ont the post o2 and report back? It will definately work if you extend and solder. I'v done that before with success.
ALSO, some of the newer TTs may have a 5-wire pre-cat o2 sensor (Nevertheless, all TTs, without exception, have a 4-wire post cat), so make sure you've got a 4-wire pre-cat sensor before getting this part. All 2000 and 2001 models have the 4 wire pre-cat. I'm not sure about 2002 and up models!!!!
so it's the number of wires that we need to worry about... ok... cuz i've saw some for much cheaper
but they only have either 1 or 2 wires. back to the point... pre or post cat are the same O2. just make sure 1- wires are enough and 2- they're long enough to reach otherwise just solder on an extender. is there a specific gauge for this extended wire?