Hi i have this car that failed its emmissons test.The fault codes on the modis is p2038 G3/1 oxygen sensor downstream 3way cat converter ,p2058 lambda control.On the kts the codes are 56 oxygen sensor behind cat aged and 88 lambda control faulty regulation before cat.When i checked it on a gas anylser the oxygen is very low so i assume there is no air leak.the co is high on low and high revs and the lambda is low .The customer wants the car asap as the retest is on tuesday.I cant get my hands on a scope meter untill nextweek so i cant check it properly.I suspect its the front sensor before the cat but at €270. i would like to be sure and would like a little help if anyboby could.