Exhaust and emissions
All articles

EVs are better for the environment than an average new gasoline vehicle no matter where you live in the U.S., according to a greenhouse gas emissions calculator created by the EPA.
By Robert Duffer
July 28, 2025

EGR stands for exhaust gas recirculation, and the EGR valve is part of a system that recirculates exhaust gas back into the engine’s intake manifold for a return trip to the cylinders it just left.
By Rick Cotta
July 27, 2025

A catalytic converter is part of your car’s exhaust system that converts harmful engine-exhaust pollutants into something less harmful to the environment.
By Nick Kurczewski
June 24, 2025

A general recommendation is to replace the positive crankcase ventilation, or PCV, valve every 30,000 to 50,000 miles.
By Rick Cotta
June 8, 2025

Ram will recall more than 600,000 heavy-duty pickup trucks to reprogram their emissions-control systems after it was discovered that the trucks contain software that allowed them to emit more than the acceptable level of nitrogen oxide.
By Jared Gall
January 11, 2024

In a word, the car exhaust smoke is caused by condensation — in two separate events. It’s similar to why you can see your breath on a winter day.
By Rick Cotta
November 26, 2023

Problems with your vehicle’s catalytic converter might first become apparent through poor acceleration, a rotten-egg smell from the exhaust, or the check-engine light coming on.
By Rick Cotta
October 29, 2023

While there are other potential causes of a sulfur smell around your car, the most likely is probably a faulty catalytic converter.
By Rick Cotta
April 23, 2023

Oxygen sensors are not among the maintenance items that need to be replaced regularly, so they typically are replaced only when they fail.
By Rick Popely
April 26, 2022

Toyota has given its 4Runner several updates for 2020, bringing this SUV’s rugged looks and off-road capability into the new decade.
By Lauren Leazenby
April 17, 2020