hey guys, looking for some help on my m300 wideband. not the typical my sensor is bad question. ive had this for about 2 years on my old setup. worked flawlessly. swapped it over to my new car and im getting some funky readings.

power at a25
ground - ive tried a24, a23 and a bolt under the dash with similar results.
brand new bosch sensor (even though i think the old one was fine)

it powers up just fine and reads 14.68 until the sensor warms up (normal)
then it will read and update quickly like normal but then it hangs on rich or air for minutes at a time this is during cruising when i know the afr is not 20:1 or 10:1. does the same thing at idle sometimes, if i blip the throttle it will start reading correctly again.

long story short, it sounds like a wiring issue but i dunno how hard power and ground can really be, is the unit malfunctioning? ive emailed plx with no response

 

unit problem. 2 years wideband lifetime is pretty long already

 

yeah i expect the sensor to go out but not the actual controller box.

anyone else care to chime in??

 

that sounds so strange how can it be a unit problem? After a couple years the unit just goes bad? I know the sensors can go bad but the unit sees no abuse. In for answers..bump

 

yea i couldnt see why the unit would go bad..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by miguel329 &raquo;</TD></TR><TR><TD CLASS="quote">yea i couldnt see why the unit would go bad..</TD></TR></TABLE>

any thoughts on the funky readings im getting?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by miguel329 &raquo;</TD></TR><TR><TD CLASS="quote">yea i couldnt see why the unit would go bad..</TD></TR></TABLE>

well is it man made and electronic?

 

any calibration factor? In for answers/experience as I just bought one and my build is almost done

 

how about the wideband and narrow band output. do they work?

before my plx display hangs, but i can continue datalogging through wideband output (white wire)

 

they seem to read the same as the display. if the display hangs on AIR the wideband output will stick on 17.86 in hondata (havent corrected the offset since the unit is reading funky)

 

bump for more ideas

 

I've read that the ground location is critical, power from a switched source in fuse box and grounded near ecu, thats just what i read, haven't done it ...yet

 

where can u get a replacement plx m300 wideband sensor?

 

Why don't you wire it directly to the battery and see how it behaves..

 

i dont have the gray wire conected and works fine plx m300 tho.

 

i thought this thing was dead. glad to see some people are still interested. my m300 is on the way to plx right now for inspection. ill post up the results ASAP. i have a new m300 that is working just fine now

either online from a plx dealer or at any auto parts store, its just a bosch sensor. 1.8t jettas use the same one. ask for bosch part# 17014