Explore why pulling out the catalytic converter can…
Does catalytic converter affect fuel consumption
by Alex
Expert answer:
Quick answer
A working catalytic converter doesn’t significantly decrease mpg. Modern engines rely on it for proper exhaust flow and emissions control. Removing it can worsen efficiency.
Detailed answer
In older exhaust systems, people speculated removing the catalytic converter might reduce back pressure and raise efficiency. However, modern vehicles calibrate air-fuel mixtures using upstream/downstream sensors. Removing the cat can cause improper fueling, check-engine lights, and even limp modes, lowering mpg.
Also, the cat’s job is to reduce harmful emissions—its slight back pressure is usually negligible for total performance. Any tiny power boost from removal is overshadowed by legal penalties, potential engine misreadings, and worse real-world driveability. Keeping the catalytic converter intact preserves stable fuel consumption and ensures compliance with emissions laws. It’s a key component for maintaining modern vehicles’ balance of power and economy.