Emissions system service required...

[stevewushu]

Just come on driving back.
Any body know what this is and how important it is?
I have just had a switch for the fuse 22 installed about 4 weeks ago. Would this have anything to do with it?

[BamfordMike]

stevewushu said:

Just come on driving back.
Any body know what this is and how important it is?
I have just had a switch for the fuse 22 installed about 4 weeks ago. Would this have anything to do with it?

Could be anything from a mass airflow meter issue to a lambda sensor, or 9 times out of 10 just a harmless gremlin.

If the light hasn't flashed red and put you in a limited power 'limp-home' mode then the problem (if there is one) isn't serious, so driving with light on is not an issue but needs checking.

It has nothing whatsoever to do with the exhaust bypass fuse being removed or a switch fitted.

The crucial thing to remember here is that the 'check engine' light ONLY illuminates (as is the legislative requirement) if the problem that has occurred is to the detriment of emissions output. So if a lambda sensor fails the light will come on, if the power flaps circuit in the airbox fail to open for example, the light will not come on.

So, the thing to remember is that rather than being a helpful light the manufacturer puts on to tell you there is a problem - it is not. The light is only there to identify an emissions sensitive problem - by law that's all the maker has to do.

Because fuse 22 removal or fitting of a bypass valve switch has no bearing on emissions output, the particular PCode triggered when that circuit fails to electrically operate does not trigger lamp illumination. Anybody who says it does simply does not know what they talking about...!

Best thing to do is buy yourself a cheap fault code read and reset tool. Post up on here the Pcode and I will tell you if it is something to warrant trip to garage with or just something that can be reset and see how it goes...

[stevewushu]

Thanks very much Mike!
I was actually going to call you on Monday about it, and to do with a central locking problem that I'm having my warranty cover (not AM warranty cover).