W202 C180 Failed Emissions Test - Lambda or MAF?

[Coptoak]

Hi All
This is my first post on here and hoping somebody with suitable knowledge can help!
Got a 1999 C180 Elegance Automatic Estate
It failed the MOT on emissions, with the following readings
Lambda 1.046 (high)
CO 0.021 (fairly low - previously been around 0.15)
HC 2 ppm (so really low - previously been about 50)
Other issues are
1. When revving the engine, won't "red line" (about 6000 rpm) just goes to about 4000 rpm and cycles up and down by 500 rpm
2. When driving, any more than a very light throttle causes a misfire and won't get to 3000 rpm. The misfire is cleared by switching the engine off and re-starting the car.

The MOT tester suggested was the lambda sensor at fault, but looking on the internet for about 5 hours (square eyes now) seems more likely to be the MAF sensor. So now confused.

If anybody can shed any light / guidance on the issue it would be appreciated.

Thanks.
Garry

 

[brigadier]

I would bet on MAF reading the symptoms, when lambda sensor goes it's not that noticable, just more thirsty usually. Maybe first try cleaning the maf - quite an easy task plenty of instructions online.

 

[PobodY]

Have you had any codes read? If so what to they suggest?