Weird PLX WB readings. HELP!

[elementalwindx]

Ok I installed my PLX M-250 as so:

WB o2 sensor into the front o2 sensor bung.

Power - to stereo fuse in the fuse panel
Ground - To the bolt that bolts the stereo to the chasis
Grey - Front o2 (simulated narrowband)
White - Rear o2 (wb signal)
*edited colors*

None of the caps or resistors are installed as I've read a few threads saying others installed it w/o them.

The problem:

Seems to be completely random but sometimes when I get on WOT, the wb will read 11-12 almost at no matter wtf I have my fuel settings in dsmlink set for, and if I turn off the car and come back later to drive it, it will flat line at 10.0 no matter what the fuel is set to.

Anyone else had this problem or know how to fix it?!

 

[scottsee]

You don't use your grey wire. Connect your simulated narrowband to the front/rear (which ever you use) o2 ecu pin. Why did you put it in the front o2 location?

Edit: Incorrect: Connect the 5v wideband (white) wire to the o2 ecu input..

 

[elementalwindx]

You don't use your grey wire. Connect your simulated narrowband to the front o2 ecu pin. Why did you put it in the front o2 location?

I put it in the front o2 cause I've seen plenty of people do it w/o problems. Sure it shortens the lifespan of the sensor but this isnt a daily driver. Its a drag only car. A toy. I have other stock normal cars to drive every day.

Why wouldn't I use my grey wire? I have to send some kind of narrow band signal to the ECU for it to get a o2 reading.

 

[90AWDTalon]

Sure it shortens the lifespan of the sensor but this isnt a daily driver. Its a drag only car.

Mine overheated in about two days when I did that.

 

[elementalwindx]

Mine overheated in about two days when I did that.

Just curious since I've never seen that before, but what does it do when it overheats?



Anybody else have an answer to the mystery above?

 

[GVR4592]

When you install a product you should follow the manufacturers specifications, if you don't then you should expect things like this to happen. Install the capacitor and move the wideband at least 24 inches away from the turbo.

 

[90AWDTalon]

Just curious since I've never seen that before, but what does it do when it overheats?

It read lean air 100% of the time. After I moved it further down the downpipe I had no problems.

 

[scottsee]

Anybody else have an answer to the mystery above?

If you do what I said in the second post, it will work. I had the same issue with my plx/dsmlink...

 

[elementalwindx]

If you do what I said in the second post, it will work. I had the same issue with my plx/dsmlink...

So moving it down another foot or so is supposed to fix this problem? Thats kinda odd sounding. I havn't had a chance to put those caps and resistors on yet due to buying a 4th dsm and soon to be taking the motor out to put in my 2nd gsx. I will be selling this shell to anyone whos interested. Its the same car that you see in my avatar.

P.S. Any way that a loose nitrous express wet kit wire could cause this? JUST A QUESTION, DO NOT FLAME ME, I DID NOT WIRE IT UP! . I'm not sure if its the ground wire or the power wire, but I'm thinking its the ground wire. Please reply asap!

 

[scottsee]

So moving it down another foot or so is supposed to fix this problem? Thats kinda odd

Not sure what you mean. Read the 2nd post agian. disconnect your grey simulated narrowband , and use the white 5V analog output wire as the input to the o2 ecu input of your choice. In this case, the front o2 ecu pin. The compasitors are used on the ground wire & I never used them, everything matches up on dsmlink/plx display.

 

[GVR4592]

Why would he want to disconnect the wideband wire? He wants to datalog his wideband with Dsmlink.

 

[scottsee]

I installed my PLXm300 3 weeks ago and spent 3-4 days trying to figure out why Dsmlink was showing 10.8 while my PLX device was showing 14.8 at idle. It was because I had the grey wire sloder into the rear o2 ecu input, not the white wire.

You can search for "PLX" on the Dsmlink forums if you like. Or Scottsee for username!

Edit Link

 

[elementalwindx]

I installed my PLXm300 3 weeks ago and spent 3-4 days trying to figure out why Dsmlink was showing 10.8 while my PLX device was showing 14.8 at idle. It was because I had the wideband (grey) wire sloder into the rear o2 ecu input, not the white narrowband wire.

You can search for "PLX" on the Dsmlink forums if you like. Or Scottsee for username!

Edit Link

I said I had the white hooked into the rear and the gray hooked into the front like its supposed to be. I just did not hook in the caps or resistors. DSMLink shows the exact same thing as my WB guage that came with my m-250. Its just its doing this freaky bullshit. I want to take it outside and shoot it.

It really doesnt help that the people at PLX devices do NOT EVER pick up the effin' phone, and sure as hell dont participate on their own forums! I'm not tryin to sound like an ass but they need to pick up on their support end of the business aspect.

 

[scottsee]

I didn't use the grey wire...

 

[elementalwindx]

I didn't use the grey wire...

Yeah but did you replace the front o2 with the wideband o2? If you did then you HAVE to use that gray wire on the front o2 sensor wire. If not then you have nothing to worry about, dont use it.

 

[GVR4592]

Did you move the sensor 24" away from the turbo and install the capacitors yet?

 

[elementalwindx]

Did you move the sensor 24" away from the turbo and install the capacitors yet?

No I'm in the process of buying back my red gst you see in my avatar and working. Its been raining too much lately to work on my car. Unforunately I dont own a garage of any kind.

 

[GVR4592]

Yeah bad weather and no garage can slow things down a lot. I've had my PLX wideband for over a year and I had it wired into dsmlink for about 6-8 months. I had no problems with it at all. I used the capacitor and installed the sensor about 30" away from the turbo. Once you get a chance try moving it and adding the capacitor. If that doesn't help try moving the ground, a bad ground can give wierd readings.

 

[Boosted98gsx]

Did you put the resistors on it? The PLX devices are supposed to use resistors to partially ground the inputs from the wideband. It gets rid of the "noise" on the readings that exist due to the exhaust static.

 

[GVR4592]

They're capacitors, and he just answered that question.

Did you move the sensor 24" away from the turbo and install the capacitors yet?

No I'm in the process of buying back my red gst you see in my avatar and working. Its been raining too much lately to work on my car. Unforunately I dont own a garage of any kind.

 

[elementalwindx]

Ok I still have not had a chance to run and get another bung welded in and to wire in the resistors, BUT I did have a spare 30min to change out the MAF with another and plug a few holes in the home made air intake. Still no change but here are some dsmlink logs.

These logs were on a trip to Advance Auto for some tools. First log is when global is set at -29 and dt is 180 on the way there, second log is at -31 and 220, on the way back home. Its running 660s. I changed the MAF for another, and RTV'd some holes in the intake pipe, but still did not notice any difference. Why the hell does this car run stupid?


*edit* 2nd log was too big to upload here.

 

[elementalwindx]

Ok everyone has been telling me to move it to the rear o2 and I finally got time today to do it, and NOW its stuck on 14.5, 14.4 and will NOT move to anything else! In the process of taking the sensor off I dented it up and bent it a little but I'm not sure if that would affect it, its on all the sensor outside the bung. It was in such an impossible spot I dont even see how I got it in there . I'm bout to hop onto the laptop soon to post a log. I also hooked up the stock front o2 how its supposed to be and its reading just fine.

Why the hell is it stuck on that now?

 

[90AWDTalon]

Ok everyone has been telling me to move it to the rear o2 and I finally got time today to do it, and NOW its stuck on 14.5, 14.4 and will NOT move to anything else! In the process of taking the sensor off I dented it up and bent it a little but I'm not sure if that would affect it, its on all the sensor outside the bung. It was in such an impossible spot I dont even see how I got it in there . I'm bout to hop onto the laptop soon to post a log. I also hooked up the stock front o2 how its supposed to be and its reading just fine.

Why the hell is it stuck on that now?

If you still have a cat converter it must be in front of it.

 

[elementalwindx]

If you still have a cat converter it must be in front of it.

I looked and looked and did not see a cat, this is a full 3" exhaust, but its at least 4' from the turbo, its under the arm rest of the car where the rear o2 sensor was.