So my car failed it’s MOT on the emissions. I serviced it 2 days before and ragged it to the garage. It’s an AMK on 145,000. The results were: Fast Idle Engine speed: Limit 2500-3000 Actual 2820 CO: Limit <0.3 Actual 5.1 HC: Limit <200 Actual 188 Lambda: Limit <0.97-1.03 Actual 0.87 Second Fast Idle Engine speed: Limit 2500-3000 Actual 2540 CO: Limit <0.3 Actual 4.3 HC: Limit <200 Actual 257 Lambda: Limit <0.97-1.03 Actual 0.89 Natural Idle Engine speed 760 CO: Limit <0.5 Actual 1.5 I cleaned the pre cat lambda 2 days prior as this caused it to fail on the same things last year. Could it be that the lambda sensor needs replacing and if so what’s causing this problem to reoccur? Are there any other problems that could cause such high readings? Any help is greatly appreciated.