Possible causes are an air leakage in the exhaust system or faulty catalytic converter. Check exhaust system for any cracks / holes. If OK suspect faulty cat. converter.
Dec 23, 2009 at 9:17 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.