1999 C280 - Code P0170, 173 will not go away. Help!
 

diagnosing a check engine light on a 1999 C280 benz. failed smog (basic), found code P0170/173. Saw the same code on a 1999 E430 (replaced fuel filter) cleared codes, roadtest, concern solved. Not so with the C280. keep finding the same code. Tune up specs in good condition, no vaccum leaks, all o2's working normally. I Am stuck! Leaning toward possible partially restricted twc? Help! This is a sold unit!!!!

Had a clk with three injectors not firing (stuck) at idle causing a lean condition at idle, with those codes. replaced injectors ok just a thouht.

MAF

Look at your adaptive values. The typical figures for mad air mass meters is 1.32 on the lower or upper partial.

I agree with ILUVMIL & STEVEBFL MAF,MAF,MAF..........................MAF