'Back to the Future' reference hidden on O'Reilly Auto's website

SPRINGFIELD, Mo. -- Go to the website of O'Reilly Auto Parts — oreillyauto.com — and search for the part number "121g."

We'll wait.

Has it loaded? Great. No, you're not seeing things. That's a product listing for a "flux capacitor."

Yes, as in the core component of the time-traveling car in the classic 1985 flick Back to the Future.

"Flux Capacitor requires the stainless steel body of the 81-83 DeLorean DMC-12, V6 2.9L to properly function," the product description reads. "Once the time machine travels at 88 mph (142 km/h), light coming from the flux capacitor pulses faster until it becomes a steady stream of light. Then, time travel begins."

"Time Travel at your own RISK!!!" the company warns, noting: "Plutonium not Available at O'Reilly Auto Parts."

"1.21 Gigawatts," it adds, channeling its best Dr. Emmett Brown impression.

To be clear, you can't actually buy a flux capacitor from the Springfield-based auto parts giant. The page states that the product is a "Non-Functional Item Displayed For Entertainment Purposes Only."

It seems to be accomplishing that goal.

The flux capacitor is not a new listing. A News-Leader reporter found mention of it as far back as November 2011 on the website Geeky-Gadgets.com, and O'Reilly spokesman Mark Merz said he believes the listing predates that by several years, to at least the late 2000s.

Every couple of years, Merz said, somebody rediscovers it, finds it funny and shares it online.

Thursday was one of those days. The page got tens of thousands of hits, Merz said.

O'Reilly was quick to respond on its Facebook page: "Every once in awhile, you all will catch wind of just how extensive our inventory truly is."

A couple of hours later, the company put out a temporary FLUX88 discount code "because where we're going, we DO need roads."

People have even recorded videos of themselves calling their local O'Reilly store in an attempt to buy the part. Couldn't that get kind of annoying? Merz demurred, saying that O'Reilly is "in the customer service business, so anytime somebody contacts us, it's not a bad thing."

Here's the thing, however. The flux capacitor listing definitely qualifies as an "Easter egg," the term for a hidden message or secret feature within an interactive work (most people associate them with video games). But it also serves a purpose beyond entertainment.

"It was originally put on there as a security tracking measure to see if anyone was using our online catalog," Merz said.

The complete list of parts offered by O'Reilly is "a valuable database," Merz said. While the company wants customers to be able to see if O'Reilly carries a specific part, it doesn't, for competitive reasons, want others to have access to the entirely of its offerings.

While someone could theoretically visit each parts category of the O'Reilly website manually, writing down the products offered, that would amount to hundreds of thousands of listings, Merz said. It's more likely that someone would try to copy the database using some sort of computer program or feature that would compile the information automatically.

That's where the flux capacitor comes in. If a copied database was subsequently published, Merz said, the company would be able to tell it was stolen from O'Reilly if it included a flux capacitor.

The fact that the general public enjoys the product listing has just turned out to be an added bonus.

"It's a fun, neat way to interface with our customers," Merz said.

So, are there other Easter eggs hidden on O'Reilly's website? Merz isn't telling.

"There could be other things out there, but this is the one we'll talk about," he said.