Engine light is on and car is chugging and misfiring when idling

What are the possible causes for a 2003 Mazda Van having engine light on and chugging and misfiring when idling? The code at Auto Zone was 2004

Are you sure this code was 2004 or was it PO204?

If the code is really P2004, then there is a problem with the intake manifold runner control.

On the other hand, if the code is P0204, then the electrical signal to the fuel injector on cylinder #4 is flukey.

Which code is it?

If it is, in fact, P2004 (but you should double check!) then this is a problem in your intake system. Your intake system sucks in air - it has a system in it to regulate the amount of air depending on what the engine is doing. Your system for sucking in extra air is either stuck open (always extra air) or there is a huge vacuum leak somewhere in the vicinity (also lots of extra air).

You need a mechanic.

Sorry–the code was 2404 evap system leak–detect pump sensor–circuit range performance AND the engine light was on and it chugged while idling after a 200 mi trip. This morning and all day today the engine light has stayed on but I haven’t felt the chugging or misfiring again.

Sorry–the code was 2404 evap system leak–detect pump sensor–circuit range performance AND the engine light was on and it chugged while idling after a 200 mi trip. This morning and all day today the engine light has stayed on but I haven’t felt the chugging or misfiring again.

Sorry–the code was 2404 evap system leak–detect pump sensor–circuit range performance AND the engine light was on and it chugged while idling after a 200 mi trip. This morning and all day today the engine light has stayed on but I haven’t felt the chugging or misfiring again.

You probably overfilled your fuel tank and got liquid fuel into the evap system. It will clear itself after a while if this is the case (provided you don’t go for broke when filling up). Clear the code and it probably will stay gone.