opel vectra c - Failed MOT on high lambda - tom1992

Hi everyone looking for abit of help my car failed it's MOT on emissions, on a high lambda reading to be exact, the car had a fault code when tested p0170 the MOT results are CO 0.00% HC 8PPM on both idle and high idle and lambda is 1.16 the car recently had done thermostat and CTS ,air filter, oil and filter spark plugs, a genuine 02 Sensor and a genuine Maf, and also some suspension work ( tie rods and anti roll bar links) since changing the MAF the car feels more responsive and the code has gone away I changed this after the last MOT test I was just wondering could this be why I failed the MOT before I rebook it

opel vectra c - Failed MOT on high lambda - tom1992

I forgot to add the car is a 04 Opel vectra C Gts 1.8 petrol, 71000 miles

opel vectra c - Failed MOT on high lambda - Big John

Any exhaust leaks (even small ones)? High Lambda indicates running lean , usually because there is a slight exhaust leak sucking in air. Was the exhaust disturbed during thesuspension work?

Edited by Big John on 03/04/2016 at 22:08

opel vectra c - Failed MOT on high lambda - tom1992

There was one on the flexi pipe but I had to have a bracket welded on to exhaust as it snapped and that was another fail the person that welded the exhaust put some filler on it, and I went back and the lambda reading was higher than the first test, the first lambda reading was 1.09 with the small leak on flexi pipe, and on retest it was 1.16 after it was patched up, but I also have to add I put in the new 02 sensor the night before the test, I've been to countless mechanics over the emissions and one said 02 sensor, the second said the 02 sensor and MAF, the third said the cat was clogged but with the HC and CO so low from what I've been reading the cat is doing its job and that the mechanic might have been looking to just get a couple of quid.

opel vectra c - Failed MOT on high lambda - tom1992

And sorry I forgot to add all the suspension work was done after the nct because they were also the bits it failed on.

 

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