PLX SM-AFR wideband jumping around (video included)
#1
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PLX SM-AFR wideband jumping around (video included)
I just installed my SM-AFR this weekend and can't seem to get an accurate reading out of it. It does seem quite close, but jumps around varying about 1 point when the sensor warms up. I didn't put any capacitor in when I installed it because from what I can find the V2 doesn't need it, but if it clears up any "noise" it just might fix this problem. The other issue that I am guessing could be the culprit is when I pulled out my old 02 sensor it was stripped out, so I bought a tap and fixed the threads. I figure it could be possible that there is a bit of an exhaust leak around the new sensor since the threads were screwed up. Any ideas?
Here is the video.
PLX wideband jumping around. - YouTube
Here is the video.
PLX wideband jumping around. - YouTube
#2
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I don't have any experience with the plx, but if its anything like the LC1 proper grounding is crucial to accurate readings. So before anything I would check your grounds. Some people go as far as running a good size ground wire (10-12gauge) to an engine ground or straight to the battery ground.
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With the PLX only one ground is needed and it is grounded to the chassis ground by my battery. I can ground it to the battery with very little effort, just to see if that helps.
#4
looks normal to be? its not going to read a straight flat number. the computer is going to be adding fuel, timing, and air and also subtracting it when needed so its a constant mix match. it will be more solid at wot i know mine jumps about like yours tho maybe i need to look into the grounding part? but from what ive understood it will jump alittle?
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Just moved the ground and its the same. Honestly I'm not sure if something is wrong with my gauge or if my tune could be a little whacky. I sat and watched it for a bit and it seems to jump between 14.3-14.8 constantly, then once every 20-30 seconds it will lean up to 15.3 or so for a second. This is at idle, haven't gotten my hp tuners in yet so I can data log everything.
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Okay, thanks guys. I didn't realize that this is normal, seems like every video I can find is of people having problems, nobody posts/videos when things work right!
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#8
Just moved the ground and its the same. Honestly I'm not sure if something is wrong with my gauge or if my tune could be a little whacky. I sat and watched it for a bit and it seems to jump between 14.3-14.8 constantly, then once every 20-30 seconds it will lean up to 15.3 or so for a second. This is at idle, haven't gotten my hp tuners in yet so I can data log everything.
#10
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Isn't the fluctuation around 14.7 the O2 sensors switching and the ECM responding by making the AFR rich then lean? Mine does it too. The O2 sensors are sort-of a discrete input to the ECM where it is either rich or lean and the ECM adjusts the afr to compensate. Too bad they don't use a wideband and let the wideband provide precise AFR feedback.