I have a 2003 Bonneville SE and I'm looking to replace the Air (Smog) Pump Check Valve but I haven't the slightest idea where it's located. Any help would be appreciated. Here's a pic of what it looks like....

Pure guess but is it attached to the air intake? Those hose connectors on the right side look like it might...

We do not seem to have a 2003 Bonnie Owner's Manual on file but we do have a 2004: 

 

I'll have a look. I wasn't sure if it was up front on the engine or in back near the tank.  I'll let you know. Thanks

I didn't see anything resembling it up front. Unfortunately I don't have the wherewithal (or guts) to jack the back end up to start digging around back there.

Ok. Well the check engine light turned off. I had taken the car to AutoZone when the light came on and the gentleman there ran the diagnostic and it came back as the air (smog) pump check valve not functioning. On further investigation I found out that the code could actually be a few different things such as the gas cap not being secured properly. Sure enough I re-tightened the gas cap and shazam, after a couple miles of driving the light switched off. 

3 hours ago, Jaxstarke99 said:

Ok. Well the check engine light turned off. I had taken the car to AutoZone when the light came on and the gentleman there ran the diagnostic and it came back as the air (smog) pump check valve not functioning. On further investigation I found out that the code could actually be a few different things such as the gas cap not being secured properly. Sure enough I re-tightened the gas cap and shazam, after a couple miles of driving the light switched off. 

Happens to the best of us. If it keeps happening you may have an issue with your gas cap or the line to the tank from the inlet. Happened to me in my G6, it's that lovely ethanol I'm sure.