Intake air temp sensor resistance increases when @ op temp. Sets p0171

Question

I a t sensor specs say resistance should decrease when warmed up. Mine increases. What symptoms would this cause? My current Symptoms are erratic, rough idle only when warm. Sets code p0171 w/ increasing frequency: now every 20 miles. Replaced m a f, i m r c (both), air filter, intake man gaskets (upper & lower), plugs & wires. Could I a t sensor be causing rough idle &/or p0171 code? Or are they unrelated?

Answer 1

On certain vehicle and at certain year , this model at this year it take a ECM just to tell you that a IAT  if there is a problem. When the engine warms up it goes to a closed loop this is where ECM manages the fuel control., You can use the IAT data to determine if there is a partial restriction in the exhaust system , this where instead of decreasing it increase.