suffolkvr6 4 Posted February 12, 2014 Report Share Posted February 12, 2014 Hi, My son's late 95 obd2 golf VR6 has just failed MOT on emission, CO on 2nd fast Idle started at 0.8, but after running for 10 mins did drop to 0.24, but quite down to 0.200 so failed! The car had been sitting for 3 years prior to driving it 15 miles to MOT I have cleaned the air filter and will take for a blast on motorway prior to retest, however, ran a diagnostic on the car with following results...please could I have your input to see if this flags up any issues... Absolute Throttle Position ..........3.9%Engine RPM........736 RPMCalculated Load Value ....2.7%Timing Advance (CYL #1)....3 degreesAirflow rate (MAF sensor) ....0.6 lb/minFuel system 1 status ....closed loop. O2 sensor faultFuel system 2 status ...unusedShort term fuel trim (bank 1) .....between 0 and -2.3%Intake air temp ....23 degreesCoolant Temp ..... 82 degreesO2 sensor 1, bank 1......0.125 V @0.0% S.T.Fuel trimO2 Sensor2, bank 1......1.120 V No faults showing on car. Comments welcome ian VR6Pete 1 Link to post Share on other sites
Ickyketseddie 89 Posted February 12, 2014 Report Share Posted February 12, 2014 Looks like you have a lambda fault. That'd certainly effect your emissions. Sent from my iPad using Tapatalk Link to post Share on other sites
suffolkvr6 4 Posted February 12, 2014 Author Report Share Posted February 12, 2014 But no fault code showing? Link to post Share on other sites
UnitedMotorsport 55 Posted February 12, 2014 Report Share Posted February 12, 2014 (edited) Lambda is well with in spec. (+/- 5%) it looks like the cat wasnt hot enough for the test, or it is inefficient. Let the engine get up to temperature (90C) and hold the RPM at ~3000rpm for a good period of time. This will get the cat hot, they need to be hot to work properly. Edited February 12, 2014 by UnitedMotorsport VR6Pete 1 Link to post Share on other sites
suffolkvr6 4 Posted February 12, 2014 Author Report Share Posted February 12, 2014 Ok will give it a go and see the results, cheers Link to post Share on other sites
VR6Pete 1,455 Posted February 12, 2014 Report Share Posted February 12, 2014 Nothing like a good Italian tune up Club Chairman Link to post Share on other sites
suffolkvr6 4 Posted February 15, 2014 Author Report Share Posted February 15, 2014 Coil pack is arcing out, which explains why is was running a bit rough and emissions being high! Also pulled the water pumps and 4 fins missing! Link to post Share on other sites
Ickyketseddie 89 Posted February 15, 2014 Report Share Posted February 15, 2014 Lambda is well with in spec. (+/- 5%) it looks like the cat wasnt hot enough for the test, or it is inefficient. Let the engine get up to temperature (90C) and hold the RPM at ~3000rpm for a good period of time. This will get the cat hot, they need to be hot to work properly. Out of interest why does it say O2 sensor fault, that's all I was going on? Sent from my iPad using Tapatalk Link to post Share on other sites
Lukey. 381 Posted February 15, 2014 Report Share Posted February 15, 2014 Would it be the unburnt fuel in the exhaust gasses? Link to post Share on other sites
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