MOT Emissions Failed

[andy_w307]

Hi guys looking for ideas my car has just failed Mot emissions and am looking for your help as to possible causes.

Its a 1.4 16V AHW mk4 Golf 1998 with 100k

O2 sensor passes the test but CO fails @ about 0.60 and HC fails at about
260

New Cat fitted and new O2 sensor due to O2 low voltage DTC.

Any ideas??

Cheers Andy

[meathead]

In the past I've seen that changing the oil and filter will allow the car to pass the emissions test. Try that.

[passat 130 tdi]

could be a WEAK spark plug not firing properly or a lead on the way out . hc is unburnt fuel . id suggest new plugs , oil and air filter , take the car for a good thrash before driving into the mot bay . cat will be cherry hot and you should see a pass hopefully.


what were the lambda readings ????

[andy_w307]

Lambda reading was 1.020 and I have had a service not two weeks ago that included NGK plugs and an air filter .

Cheers