rough idle (does not stall, steady @700-750rpm)...unnusual smell in exhaust pipe

i already clean all hose,throttle,iac valve,map sensor,vacuum solenoid valve,spark plugs is only 9 months,oil is due come 500km more.. i noticed idle is somewhat missing power..but it does not stall.. it hesitate in irst gear 3rd and 4th i can race the engine power is acceptable..irst gear..when you are in a ramp you need to rev egngine or you stall.. exhaust sound is dut dut dut dut.. per ect (letter '' '' is not '' ''untcnioning in my keyboard see?) idle sounds like a continuous rhythm drrrrrttt.. i suspect the o2 sensor is bad or the ecm module need to be scan? (i just reset the ecm nothing works..pls advice me what to do this is my only car and can't aord a new one or a good secondhand Honda civics