Car emissions are a major source of pollution.

Cars and trucks emit twenty percent of all greenhouse gases emitted in the United States,

which is the second largest greenhouse gas emitter in the world, It was the largest for decades. This puts vehicle emissions in the United States as one of the largest greenhouse gas emitters in the world. A lot has to change to make meaningful emissions reductions to stop even-worse impacts. In addition to any roadblocks presented by legacy, vested interests, governments and individuals and companies have to heavily invest in a wide array of technologies and incentives to make it work.

Depending on the problem, possible solutions may include replacing damaged components such as the oxygen sensor, catalytic converter, or a vacuum hose.