When I burn my mp3s onto audio cds using Nero it seems like it loses sound quality. Maybe it's just because I'm used to listening to my mp3s with Foobar2000 and my Santa Cruz w/ it's equalizer but it still seems to me like I am losing quality. Am I just imaging it or is this true?

I don't think so.If you burn low quality MP3 (say <=128kbps encodings) to CDDA format you'll get poor quality when played on decent audio equipment.
If you burn high quality MP3 (say Lame -alt-preset standard) to CDDA format you'll get good quality for a wide variety of audio material when played on good audio equipment.
From the quality point of view , burning MP3 to CDDA format is only encouraged when you can't get the original audio material or lossless encoding or any other higher quality lossy encoding (OGG , MPC or MP4 at mid/high bitrates).

Maybe Nero doesn't do 16 bit dithered output? Time to play with Foobar's diskwriter and burn cds from wavs.

Nero's mp3 decoder shouldn't sound any different from Foobar's. I think it's already been established that Foobar's dithered output makes no audible difference for most people.

If you like the sound of your equalizer, you should use Foobar with diskwriter and apply the equalization to the audio you're burning to CD. Or you can just turn the bass boost on your CD player to full, it will probably have the same effect.

You could do tests to find out if there really is a difference and what's the reason for it.

1st:
- Rip a CD you burned from mp3s with nero -> a.wav
- Decode the mp3s directly, e.g. with lame -> b.wav
- use foobars diskwriter with same settings you use for playback -> c.wav
- Try to abx a vs. b, a vs. c, b vs. c

2nd:
- Rip + encode (to mp3) an original CD of your collection
- Burn a CD-R(W) with nero from the mp3s
- Compare both.

Some more possible reasons for differences:
- Your mp3s have high peaks and cause foobar2000s limiter to kick in.
- Some older versions of Nero have a buggy mp3 decoder - you haven't said what version you use.
- If you play back "virgin" mp3s with fb2k without any dsp enabled, including volume controll, limiting ..., there won't be any difference to other decent mp3 decoders, but if the mp3s are mp3gained, fb2k's dither will give an (at least theoretical) advantage.

The CD contain a lossless copy of a playback of the MP3, the difference must come from the CD playback itself.
Use the "digital mode" to play CDs (Win 2k, Win XP, WinMe ?, in the properties of the drive), so that their sound follow the same path as MP3s in the soundcard.