I have MAF and IAT sensors cleaned as per Jim's instructions. Duty cycle on idle is 2-9% and at 2500rpms 23-35%. Cycle jumps to 49% if you give a little gas and let go. After it jumps to 49% it slowly drops to 2-9%. Engine starts to run a little rough. Exhaust smell bad. Does it mean that I have mixture too lean? No codes are stored.
Any ideas what can cause lean mixture?
Please help

__________________
1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod