Since fitting a air/fuel ratio gauge. It seems to act very weirdly

When I start the car up, it flicks around for about 5-10 seconds. Then once slightly warm just goes off the scale and stays there permanently.

Is this a lambda sensor going crazy? Do I need to replace/clean it? Or is it something else?

I don't have any warning lights up on the dash.

How did you wire it up?

Mine dances around a lot between lean and rich, but doesn't ever do what you describe.

The following link shows how I connected mine:

http://www.pimpmyskoda.co.uk/Gauges.htm

I followed your guide to the letter. Wired from the correct black cable under the car. Up and through the bonnet and across the dash to the gauge.

It kinda works for a few seconds. If I pull away right after I start the car, it works to a degree. The needle does move correctly into the normal range. But still then goes off the top of the gauge. Think my sensor is a bit deeed. Got Skoda to check the sensor specifically and they said it was a little erratic, but still nothing on the dash.

I've got your guides Bookmarked they are so good!! Keep making me want to mod my car more and more!

I followed your guide to the letter. Wired from the correct black cable under the car. Up and through the bonnet and across the dash to the gauge.

It kinda works for a few seconds. If I pull away right after I start the car, it works to a degree. The needle does move correctly into the normal range. But still then goes off the top of the gauge. Think my sensor is a bit deeed. Got Skoda to check the sensor specifically and they said it was a little erratic, but still nothing on the dash.

I've got your guides Bookmarked they are so good!! Keep making me want to mod my car more and more!

:p Thanks - that's why I do them

Not sure what to suggest - sounds like it could be the sensor. I know the front wideband sensor is about 40 quid from Ebay and not hard to change - but not sure how much the rear one.

Are you guys trying to run a AFR gauge from the rear (4-wire ) sensor? Is the Cat still fitted?

If so then you will never get any sense. If the cat is working and the system is operating in closed-loop (ie cruise conditions, not accelerating or full throttle) then the back sensor output just sits static. The second sensor is there purely to monitor that the cat is functioning correctly and has nothing to do with fuel control and doesn't switch in the way you are expecting.

Neither can you get a signal off the front widebend sensor for the AFR gauge. The only option is to get a dedicated narrowband sensor fitted pre-cat to drive the gauge.

My car failed emissons on its MOT. Took it to a garage. The emissons where fine when the car started but failed as soon as it got warm. Very eractic. They did the test again with the engine at 5000revs. Emissons where fine. It was the front lamba sensor.