Fuel trim issue: 'Mini' problem, but big headache

Vehicle Application:

•Mini 2005 Cooper 1.6

Avg. Reported Mileage:

• 77,142 miles

Direct Hits:

• 372575

Customer Concern:

Code P2096 indicates that the rear O2 sensor registers a long-term lean condition. There is a technical service bulletin, No. M12 01 06, that addresses this problem. Small leaks at exhaust system welds and flange gaskets as well as at bungs for O2 sensors are relatively common, and can be found by pressurizing the exhaust system and using a soapy water solution to look for leaks, indicated by bubbles.

Tools Used:

• Scan tool
• Injector cleaner
• Fuel injection tester
• Smoke machine
• Exhaust gas analyzer

Steps

tests/procedures:

1. Check long-term fuel trim values. Expect a value >5 percent positive.