Can an oil leak cause damage to a catalytic converter?

Yes, an oil leak can cause damage to a catalytic converter. When engine oil leaks into the exhaust system—often due to worn piston rings, valve seals, or a blown head gasket—it can burn inside the catalytic converter. This burning oil creates excess heat and deposits that can clog the converter’s honeycomb structure, reducing its efficiency and potentially leading to complete failure. Over time, this can trigger the check engine light, increase emissions, and decrease engine performance. Addressing oil leaks promptly is crucial to avoid expensive catalytic converter repairs or replacements.