I recently removed my front bumper to switch my headlight bulbs but couldn't figure it out so when I put it back on. The left side won't stay in place. It comes out. I have to push it in constantly. Am I missing a part that holds it?

 

I'd take it back off and reinstall, making sure each screw bites and holds firm.
I've had mine off and don't remember it being difficult. You probably just overlooked something simple.

 

There's a pic

 

Try loosening up all the bolts and remove the clips located directly under the front lip of the hood. Apply pressure on the area to align it and tighten those same bolts you loosened. Sometimes the retaining bracket that the side corner lens attach onto(white in my '04, I have seen it in black) breaks even the one under the headlight lamp(black one). At the lip of the bumper in your picture, there are holes, those are suppose to clip on the bracket under the headlight. Look closely, you may have to just tinker with it a little.

 

I did remove this black piece under the headlight and then I was like "this is useless" and I didn't put it back. Is this what it needs?

 

Lol. Yea usually stuff has a purpose. When something isn't working right your thoughts should immediately go to what you know is wrong and then adjust to looking for new wrong things later. This thread makes me chuckle

 

Yep! I hope you didn't snap that in half and tossed it in the trash.

 

I see zip ties in you future

 

That's odd, i was able to replace my headlight bulbs without taking the front bumper off. Should have been able to pull the front wheels off and reach through behind the mud guards.

 

I didn't think about it much but it was just under the headlight being annoying so I just unbolted and I think it might of got tossed out. Does anyone know the name to buy a new one

 

I have the same exact issue except on both sides. I replaced both retainers (even though it turns out i didnt need to) and still cant get it to stay. driving me crazy!