What is that huge black box (2 ft long, 8-10 inches diameter) mounted on the frame rail under the passenger floorboard?

http://www.ebay.com/itm/Chevrolet-Si...US_Cars_Trucks

Scroll through a few shots, it is only on the passenger side......What is it?

DEF tank.

[ATTACH=CONFIG]514581[/ATTACH]

http://blogs.dieselpowermag.com/6744...uramax-owners/

Ok that explains it........man it is UGLY hanging down there! Why couldn't they put it out of sight on the other side of the rail! I hate running boards/steps but it looks like the only way to cover that box!

A nice set of running boards or nerf steps will hide that tank. There is also a way to remove it.

Really??? Tell me more???

We'd tell you but then we'd have to kill you. Or make you ride in a Bayliner for 3 days straight.

It is illegal to remove it......

Wannabe

Spend some time over here - http://www.dieselplace.com/forum/

Read and Search, then ask any questions. 3 years in on the DEF systems, there are not many questions left unanswered.

Remove it? Naw. Convert it to a Crown Royal dispenser and the party never ends!

www.duramaxforum.com
Any and all questions about diesel exhaust fluid system. It can be removed for "off road" purposes.

Good luck.

Those "off road" tuners are getting harder to come by since the government crackdown last year, but they're still out there. If you don't want to delete the emissions, places like Duramaxtuner.com are doing amazing things with everything left intact.