4Pcs Air Fuel Ratio Oxygen Sensor Up Downstream for 04-06 BMW 3.0L Auto Trans

What is 4Pcs Air Fuel Ratio Oxygen Sensor Up Downstream for 04-06 BMW 3.0L Auto Trans?

This is a four-piece replacement oxygen sensor set from Lab Work Auto, bundling two upstream air-fuel ratio sensors and two downstream O2 sensors for 2003-2006 BMW models running the M54 inline-six. It is sold as a complete bank-by-bank refresh, so you can replace all four sensors in one job rather than chasing trouble codes one position at a time.

Key features

• Complete four-sensor kit — two upstream AFR sensors plus two downstream O2 sensors covering both banks.
• Correct wiring layout — two 4-wire sensors and two 6-wire sensors to match factory connector positions.
• Direct plug-in fitment — no splicing, soldering, or adapter pigtails required when the connectors match your harness.
• Broad BMW coverage — fits 325i, 325Ci, 330i, 330Ci, 525i, and 530i applications across the 2003-2006 range.
• Cross-references included — interchanges with part numbers 234-5137 and 234-4473 for easy verification.
• Brand new units — not remanufactured, so internal heater circuits and sensing elements start fresh.
• Value bundle pricing — listed at $77.31 for all four pieces, versus paying per sensor at a dealer counter.

Who is 4Pcs Air Fuel Ratio Oxygen Sensor Up Downstream for 04-06 BMW 3.0L Auto Trans for?

This kit is aimed at BMW owners and independent shop techs dealing with check-engine lights, P0130-series codes, rough idle, or failed emissions tests on an aging E46 or E60. Installation is realistic for a confident DIYer with a proper O2 sensor socket and a lift or jack stands, since the rear sensors sit under the car and the fronts live just off the exhaust manifolds. Before ordering, you should compare your existing connectors against the photos to confirm they match.

How does 4Pcs Air Fuel Ratio Oxygen Sensor Up Downstream for 04-06 BMW 3.0L Auto Trans compare?

Compared with buying genuine BMW or premium European-brand sensors individually, this bundle costs a fraction of the price while still delivering direct-fit connectors and the correct wire counts for each position. Versus generic universal sensors that require cutting the factory plugs, it saves significant install time and avoids the reliability issues that come with crimped splices. It sits in the budget aftermarket tier, so shoppers chasing OE-stamped Bosch or NTK units may prefer those, but for a full four-corner replacement at one price, this set is hard to beat.