Thumping noise

There is a light thumping sound, the best I can describe it coming from the air filter box area sounds like it could be inside. If I rev the engine a little bit it usually does it when its going back to idle and sometimes when its just idling. Kinda sounds like it has something to do with the engine sucking in air.

A wild guess would be the air filter is not seated properly in the air box?

I think my CE has the same sound, it's like a low popping noise?

The engine runs and idles smooth though. The filter is OK.

Yea, kinda like a popping sound. Doesnt seem to be running to bad other than needing oil change and maybe plugs. Air filter is pretty new, ill check it to make sure its in right.

A miss fire.....my Evergreen is doing the same thing. Hopefully yours isn't doing it for the same reason mine is.

A way to figure out which cylinder it is -- Have someone hold the car in Drive while you listen to the thumping noise. Individually unplug each injector connector (one at a time, replugging back in when done) until you notice NO change in the thumping noise. Once you find THAT cylinder then you'll know which one is have the misfire. You will notice a distinct change in the idle/sound of the engine on the cylinders that are working fine, then when you get to the culprit cylinder, you'll notice NO change. Once you find THAT cylinder....start diagnosing. If you're good at the sound test, you can swap the coils/wires (depending on year) to the adjacent cylinder. Re-test using the sound check and if the misfire moves, then you know you have a bad coil/boot/spark plug wire.

Hope this helps....