My 2007 Daihatsu has failed the national car test on emissions. The readings at 3500rpm are:
Lambda: 1.10 (normal range 0.97 - 1.03) CO: 0.02% volume (normal range below 0.20%) HC: 11ppm (normal range below 200ppm)
To me, this sounds like the exhaust has a hole - which seems likely as it's rather rusted. I have yet to hold my hand over the exhaust, and listen for the noise of air escaping.
My questions are:
- Can someone confirm that this looks I need to replace the exhaust?
- Should I also replace the lambda sensor?