BMW 740i Oxygen Sensor Replacement at your home or office.

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Oxygen Sensor Replacement Service

How much does a Oxygen Sensor Replacement cost?

On average, the cost for a BMW 740i Oxygen Sensor Replacement is $320 with $180 for parts and $140 for labor. Prices may vary depending on your location.

CarServiceEstimateShop/Dealer Price
2000 BMW 740iV8-4.4LService typeOxygen Sensor - Front/Upper/Upstream ReplacementEstimate$515.68Shop/Dealer Price$612.15 - $887.39
1998 BMW 740iV8-4.4LService typeOxygen Sensor - Front/Upper/Upstream ReplacementEstimate$506.67Shop/Dealer Price$600.05 - $872.97
2000 BMW 740iV8-4.4LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementEstimate$766.71Shop/Dealer Price$925.14 - $1393.12
2001 BMW 740iV8-4.4LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementEstimate$766.71Shop/Dealer Price$925.14 - $1393.12
1997 BMW 740iV8-4.4LService typeOxygen Sensor - Rear/Lower/Downstream ReplacementEstimate$506.67Shop/Dealer Price$602.67 - $877.55
2017 BMW 740iL6-3.0L TurboService typeOxygen Sensor - Rear/Lower/Downstream ReplacementEstimate$1139.25Shop/Dealer Price$1303.31 - $1779.77
2015 BMW 740iL6-3.0L TurboService typeOxygen Sensor - Front/Upper/Upstream ReplacementEstimate$1747.49Shop/Dealer Price$2068.09 - $3004.09
2001 BMW 740iV8-4.4LService typeOxygen Sensor - Front/Upper/Upstream ReplacementEstimate$506.67Shop/Dealer Price$600.09 - $873.04
Show example BMW 740i Oxygen Sensor Replacement prices

What is the Oxygen Sensor all about?

With each new model year, manufacturers are adding more oxygen sensors to better manage engine operation. Some high performance engines have an oxygen sensor for each cylinder as well as one for the rear of each catalytic convertor. The sensors are located either underneath the hood or underneath the car. The oxygen sensors are connected (screwed) to the exhaust pipe, either in front or back of the catalytic converter. The front (upstream) sensors measure the amount of oxygen in the exhaust system. The purpose of the front oxygen sensor(s) is to measure how rich or lean the gases are as the gases exit the combustion chamber. Depending upon whether the exhaust gas is lean (high in oxygen content) or rich (low in oxygen content), the amount of fuel entering the engine is adjusted by the engine management computer to try and maintain an ideal mixture that produces the lowest emissions output from the catalytic convertor.

Rear (downstream) sensors are located behind the catalytic converter. The purpose of the rear oxygen sensor(s) is to monitor the oxygen content of the exhaust gases leaving the catalytic convertor.

If one or more of the oxygen sensors are faulty, your car may not pass the emissions test. If you drive your car with a faulty oxygen sensor, you may get poor gas mileage and it can damage the catalytic converter.

Oxygen Sensor-MATROX-1

When replacing the oxygen sensor remember:

  • Many oxygen sensors are damaged by leaking oil or coolant. If that is the case, the cause of that leak needs to be identified and repaired, or else the replacement oxygen sensor will be damaged as well.
  • New vehicles require specific oxygen sensors, and not the universal sensors that were common prior to 1996.

How it's done:

  • Scan the computer in the car for codes.
  • Inspect for vacuum leaks and holes in the exhaust system.
  • Remove and replace the oxygen sensor if it is bad.
  • Check electrical connections.
  • Check for proper operation of oxygen sensors.
  • Clear diagnostic codes.
  • Test drive car.

Our recommendation:

Keep up with the tune-ups. If check engine light is on, don't drive the car too long without getting it inspected. If check engine light is flashing, pull over and get the car towed to avoid costly repairs. Ask the mechanic to inspect the vacuum hoses and leaks in the exhaust system. If the vacuum hose or exhaust system is leaking, it will display an oxygen sensor fault code. Replacing an oxygen sensor may not fix the problem.

What common symptoms indicate you may need to replace the Oxygen Sensor?

  • Check Engine light is on.
  • Car is getting poor gas mileage.
  • Emission test fails.

How important is replacing the oxygen sensor?

Your vehicle has multiple oxygen sensors, and they all help the car run optimally. The front sensors measure how much oxygen is in the exhaust stream to measure how rich or lean the gases leaving the gas chamber are. The rear sensors measure the oxygen content of the gases as they leave the catalytic converter. The oxygen sensors then relay this information to your vehicle’s electronic control unit, so that it can adjust as necessary. Because cars depend on an ideal fuel-to-air ratio to function optimally, the oxygen sensors are leaned on for engine performance. When your oxygen sensors fail your car will run less smoothly, get worse mileage, and have worse emissions.

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Andrew

16 years of experience
657 reviews
Andrew
16 years of experience
BMW 740i V8-4.4L - Starter - Beaverton, Oregon
Andrew came out last week and troubleshot my car in the garage and said it was the starter motor. I had suspected it was the starter motor but wasn't quite sure so it was good to get a verification. I have to admit, I was kinda skeptical about this home mechanic thing so I was taking a wait and see attitude until after he came back for the repairs. Both times, Andrew showed up early..which is fine by me. Today, when he came back, he went straight to work installing the new starter motor and changed the oil. Car fired right up so I was happy and I've started it a few more times and it is working well and I don't see any oil leaking. If there was a half star option, I'd deduct 1/2 star. Andrew needs to carry some oil rag buckets or something since he put a bunch of oily rags next to the sidewalk and I went out to clean them up (my dad saw them on his way out and text me and I said, it can't be the mechanic) and had to dig up some dirt since the rags were leaking oil. I'm not sure why he thought placing them on the ground was a good idea but oily rags on the ground is never good especially when it's raining. Overall, I'm happy with the repairs and the experience and will definitely consider using the service again especially since I'm working from home and don't get into my normal shop anymore.

Andrew

12 years of experience
962 reviews
Andrew
12 years of experience
BMW 740i V8-4.4L - Noise from engine or exhaust - Shawnee Mission, Kansas
i thought it was an Adjusting pulley. Andrew looked and said that the fan blades were no aligned with the the Fan Housing. We then listened and I told him it could be the impeller in the water pump but the sound wasn't "metallic". He said that the impellers in my water pump were a plastic composite. He was right on both accounts. What a PRO! I recommend this guy to anyone. He was on-time, courteous and RIGHT in the diagnosis. I'll ask for him again.......next time something else breaks.

Eduardo

20 years of experience
570 reviews
Eduardo
20 years of experience
BMW 740i L6-3.0L Turbo - Brake Pads Replacement (Rear) - Houston, Texas
Edwardo was professional, knowledgeable and very efficient. He continues to impress me to the point that moving forward I will only trust him to provide service needs. Awesome!!

David

11 years of experience
199 reviews
David
11 years of experience
BMW 740i L6-3.0L Turbo - Car Battery Replacement - Windermere, Florida
Very knowledgeable and respectful!

Excellent Rating

(48)

Rating Summary
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Number of BMW 740i services completed
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services done by our mechanics
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