2006 nissan altima 2.5 L intermittant missfire.

The coolant odor is the most concerning to me and could be causing the short to the coil or injector harness to the cylinder misfire. Should have stored a code for the misfire that would tell you what cylinder is misfiring and you may find a coolant leak in that area .

Iam having the same problem. I've replaced the spark plugs,ignition coils and catalyst converter with no luck. Did you happen to find your solution?

Its definatly a idle air control valve if runs il under throttle but sputters all hell doing everything but stalling and even stalling its def idle control valve should be some sort cylindrical thing attached to the throttle body or along the intake system, it when removed has a spring with attached valve inside the spring rotates when ur at idle or off gas and that closed the main throttle body its cars emergency life support, it's how she breathes when she has her mouth shut lol good news go get a can of carb cleaner (carborator/and or carbon) and spray into hole with daif spring, if said hole has no visible spring just a bunch of black gooked all over, well the black clearly ruined her but even then spray and pray and b re hold spring and guts hopefully intact reattach n goood to go if the spring failed have replace but still a cheap enough fix.