mikjel

I have just bought and innstalled a PLX M300 wideband O2 in my car. I have mounted the sensor vertically in the exhaust just in front of where the cat once was.

My problem is that the sonsor seems to be much to sensetive or something.

Every second the numbers on the display seems to be changing 20-30 (?) times, and within one second I am seeing everything from 14.0:1 to 15,5:1 (cruising) even if the throttle is in the same position and the rpm is constant.

At WOT I am seeing everything from 11,0:1 to 12,5:1 within one second even if the rpm is constant. The numbers on the dislpay are changing so fast (it looks like 20-30 times each second).

I would really like to know if I am running 11,0:1 or 12,5:1, or should I just take the average 11,75:1?

Is this normal, or should the numbers on the display be more stable?


Mikjel.

turbite

Well, you will see some resonance around 14.7 at idle/normal driving. (mine goes from 14.9 to 14.2 and back)

I'm not exactly sure how you are at WOT and keeping rpm constant... ?
Sounds like normal operation to me.

mikjel

When I am going 160mph the rpm is near constant
(not rising much) in one second.

turbite

Hahaha.
You make a valid point.

Brett

guys do you need a different bung in the exhaust for the wideband or can you use the same one as the original o2 sensor?

Edman951

The fluctuation is normal.
The sensor is sending its reading many times per second so its normal that its not constant.
You may think the idle is steady but its varying at good +/-50rpm up and down on idle.
This is very evedent on my car with the Link hand programer for the Map kit. Because it has a digital rpm readout and it really goes up and down alot. Even while crusing the rpm fluctuates.a bit.
But this is my car with the Map kit.

Maybe Danno will confirm that even with just the chip its normal.

Hope this helps

adrial

The factory location is too hot and is under too much pressure for most wideband sensors.

You need to weld on another bung and it needs to be located after the turbo.