Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Exhaust System
HINT: The illustration displays the exhaust system for the XC90.
The three-way catalytic converters clean by oxidizing carbon monoxide (CO) and hydrocarbons (HC) to water and carbon dioxide (CO2 ). Nitrous oxides (NOx ) are reduced to nitrogen and water. The catalytic converter transforms over 98 percent of these substances during normal operation. Lead contaminates in the fuel can damage the catalytic converter, quickly rendering it inoperable.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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