(VX/HX) The counterfeit L1H1/L2H2 O2 sensors: making them, making them better
After reading through a bunch of threads about the cheap eBay L1H1/L2H2 O2 sensors, it looks like these are being made by starting with some inexpensive VW/Audi 5-wire sensor in the NTK line, and then adding a Sumitomo connector and a resistor. If these can be sold for under $100 (e.g., $60 from evalero, $79 from global automotive) - presumably at a profit - then the VX/HX community ought to be able to make them cheaply too, and maybe more functional as well.
Based on all of the complaints on how these sometimes fail to perform, there is something not quite right in the final product - maybe the sensor isn't an exact match or the calibration resistor isn't being done right. It may be too that even when these don't produce a CEL that they aren't performing as well as they could if a better counterfeiting job was done (e.g., the counterfeiters might not be putting much effort into using the right value calibration resistor - maybe even just using the same resistance for all of them).
You can clearly see the calibration resistor, Rcal, in black heatshrink spanning pins 3 and 4 of the connector. You can also see a line of text engraved above the blue sticker (seems to include 'NTK JAPAN') and another line near the rubber band. Also, bugish pointed out in post #170 of thread 5377 ("$79 5 wire O2 sensor - who has bought one?") that underneath the sticker on his was the marking 'VW Audi'.
So, to unravel what is going on and maybe be able to make these on our own - and maybe make them better - could some of the people that have these counterfeit L1H1/L2H2 sensors kindly provide some information about them:
1) What text is engraved on them, and where is it - including any text hidden by the blue (or any other) sticker? Photos would be a big help. The purpose of knowing this is as a clue in figuring out the NTK catalog number of the sensor being used.
2) What value is your Rcal? This is easy to measure: just disconnect the sensor's plug from the engine wiring harness, and put an ohmmeter across pins 3 and 4 of the sensor's connector (if the picture showing the resistor isn't still in thread 8372, 3 and 4 are the pins with the heatshrink-covered resistor hanging out of the wire-side of the connector).
3) Is your O2 sensor thowing CELs (and if so, which ones and under what conditions)? If it turns out that all of the counterfeits are using the same value Rcal, eliminating the code 48 CELs on those that have them might be as simple as just changing to another Rcal value. Also, if it turns out that all of the counterfeits are using the same value Rcal, then those that aren't throwing CELs probably aren't reporting accurate AF mixture values to the ECU and might benefit from being calibrated right.