Originally posted by tw0wheelin:
The 171 will probably come back, but it's not really harmful. The O2 sensors get weaker over time (60K miles is typical) and start indicating a lean mixture. Computer tries to compensate with more richer mixture which turns off light for awhile, but burns more gas=less mileage. Bank 1 is hardest to reach being between the engine & firewall. New sensors are about $60.
So is it a real PITA, or just more difficult than others?
