By TOM KRISHER
AP Auto Writer

DETROIT (AP) _ Eleven automakers are expected next week to reveal which models are being added to a massive recall of air bags made by Takata Corp.

On Tuesday, the U.S. National Highway Traffic Safety Administration announced a deal with Takata to declare millions of its air bag inflators defective and expand the recall from 17 million to 33.8 million. The air bag inflators can explode with too much force, spewing metal fragments into the passenger compartment.

Automakers including Toyota Motor Corp. and Honda Motor Co. are scrambling to figure out which models are now covered.

Many questions about the problem remain unanswered as an investigation continues, but here’s what you need to know about the largest automotive recall in U.S. history:

THE DANGER

In a crash, the air bag propellant can burn too fast, blowing apart a metal inflator canister. Six people have died and at least 105 have been injured due to the problem.

THE SOLUTION

Takata’s agreement with U.S. regulators added millions of cars and trucks to existing recalls by 11 manufacturers _ BMW, Fiat Chrysler, Ford, General Motors, Daimler Trucks, Honda, Mitsubishi, Mazda, Nissan, Subaru and Toyota. Takata will need 33.8 million inflators for the repairs _ so far it has made 3.8 million. At Takata’s estimated rate of production, it will take 2 1/2 years to crank out enough inflators to fix all the affected vehicles.

DOES THE EXPANSION COVER MY CAR?

The automakers don’t yet have the answer. They are busy taking data from Takata and matching it to production records to see which models have the faulty inflators. Once they determine that, the companies will file papers with NHTSA detailing the models, probably next week. It’s likely that the expansion will involve additional car and truck models beyond those that already have been recalled.

HOW TO CHECK ON YOUR CAR

If your car has the faulty air bags, eventually you’ll get a recall notice in the mail from the manufacturer. But many won’t get notices until parts are available. In the meantime, you can enter your vehicle identification number into the NHTSA website, https://vinrcl.safercar.gov/vin/ on see if you’re part of the recall. The number is stamped on the driver’s side dashboard near the base of the windshield, or it can be found on state registration cards. It’s wise to keep checking if you suspect your car is involved because the automakers are still determining which models to include.

SHOULD CAR OWNERS WORRY?

Takata says inflator ruptures are rare. In paperwork filed with NHTSA, the company says its air bags have inflated in crashes 1.2 million times in the U.S. Of those, 84 inflators have exploded. That’s only 0.007 percent of the total. But even such a remote possibility can unnerve some drivers. So if you have a recalled model, or if you’re awaiting word on your car, check with your dealer often to see if parts have arrived so you get on a priority list. Some manufacturers such as Honda, Toyota, BMW and General Motors offer loaner cars for at least some recalled models. Other automakers could provide them if you persist. It’s worth trying.

WHAT IS THE GOVERNMENT DOING?

NHTSA pushed Takata to expand the recall, and the agency has filed paperwork to take control of the recall. It has the power to manage production, distribution and installation of replacement parts, including lining up other manufacturers to make more inflators. Inflators would go to high-humidity areas along the Gulf Coast first because the risk is highest there. Older cars would get priority as well, because the longer an inflator is exposed to high humidity, the greater the likelihood of failure.

SOME REPLACEMENT INFLATORS MAY BE BAD

Some drivers who already had inflators replaced may have to do so again because automakers have replaced some inflators with new ones that now are defective. But NHTSA says people should still get their cars fixed because a new inflator _ even if it’s defective _ is better than an old one.

I HAVE A NEWER CAR WITH A TAKATA AIR BAG

This is another tricky spot. NHTSA says there haven’t been any problems with inflators in cars newer than the 2011 model year, so those aren’t being recalled. The rest of the recalled cars date to the early 2000s. But models keep being added to the recall, and investigators are looking at the safety of all Takata inflators. To be safe, ask your dealer if your car’s air bags are made by Takata and check periodically to see if it’s part of any recall expansions.