Exhaust Leaks

If exhaust system has large leaks, exhaust system negative pressure pulses can cause outside air to be drawn into system and past O2 sensor. Vacuum or crankcase leaks can also cause a lean condition. If Code 44 is intermittent, proceed to the INTERMITTENTS in TESTS W/O CODES - GASOLINE article.

Fig 1: Code 44 Schematic (All Models) Lean Exhaust Indication

Fig 2: Code 44 Flow Chart (All Models) Lean Exhaust Indication