Hello guys,

I have a same problem with two cars. First a GMC Suburban 1999 1GFKFK16R5XJ775743, the lamda is too lean. CO 0.01 Lamda 1.48 O2 0.18 HC 34

Lamda must go to 1.00 Does this problem has to do with the new USA emission system. Or Catalysator U9. Th... Login to read more.