My car has had a pretty bad misfire for a while now. Ive done a full tune up on it, ALL new filters, even fuel, plugs, wires, cap, rotor. It runs ok at higher rpms with a smaller miss but wont idle for anything. somedays it runs decent most it runs horrible....

No check engine light, should i check any sensors? maybe the new plug wires are already bad? after the inital tune up it ran great for about a week...

 

check timming and probably your iac valve is bad or the housing got build up of residues,also clean the maf