NTK Lambda/Oxygen O2 Sensor - NGK 91515 / OZA770-EE54 - 4-Wire 500mm - Fits BMW 1 3 5 7 Series & X1, Mitsubishi Colt Z30/CZC, Smart Forfour 454 - Upstream/Downstream Direct-Fit Replacement

NTK 91515 OZA770-EE54 4‑Wire Exhaust Gas Oxygen Probe 500 mm Lead

Restore crisp fuelling, smooth idle and clean emissions with this OE-grade NTK by NGK exhaust oxygen probe. Part numbers NGK 91515 and NTK OZA770-EE54. This heated 4‑pin, 500 mm lead, plug-in mixture sensor is a direct-fit unit for selected BMW petrol models, Mitsubishi Colt Z30 and CZC, and the Smart Forfour 454. Suitable for primary pre-cat and secondary post-cat positions depending on the application, it delivers fast light-up, stable feedback to the ECU and reliable closed-loop control.

We run these sensors on our own cars and our customers consistently report better drivability, improved MPG and swift resolution of mixture-related warning lights. If you are chasing an emissions fault, rough running or poor fuel economy on a compatible model, this NTK 91515 OZA770‑EE54 is a proven fix that keeps petrol engines performing as they should.

Why this NTK probe is a winning choice

• OE quality from NTK by NGK for precise AFR feedback and durability
• Heated 4‑wire design for rapid warm-up and stable signal at idle and cruise
• 500 mm harness with factory-style connector for a true plug-and-play install
• Direct replacement for front or rear mixture sensor on listed vehicles
• Helps restore fuel economy, throttle response and MOT-friendly emissions

Part numbers and tech details

• Brand: NTK by NGK
• Part number: NGK 91515
• NTK code: OZA770-EE54
• Circuits: 4 wires
• Lead length: 500 mm
• Fitment position: pre-cat front or post-cat rear depending on vehicle, Bank 1 Sensor 1 or Bank 1 Sensor 2

Vehicle applications

Please check your vehicle details below and contact us if you need confirmation. This probe fits the following petrol platforms where specified:

BMW petrol applications

• 1 Series E81 E82 E87 E88 - 116i, 118i, 120i
• 3 Series E46 - 316i, 316Ci
• 3 Series E90 E91 E92 E93 - 316i, 318i, 320i
• 5 Series E60 E61 - 523i, 525i, 530i
• 5 Series F10 - 523i
• 7 Series E65 E66 E67 - 730i and 730Li
• X1 E84 - 18i

Mitsubishi

• Colt VI Z30 - 1.1, 1.1 LPG, 1.3, 1.3 LPG, 1.5, 1.5 CZT
• Colt CZC Convertible RG - 1.5 Z23 and 1.5 Turbo Z23

Smart

• Forfour I 454 - 1.1, 1.3, 1.5 variants

Tip: primary equals pre-cat front, secondary equals post-cat rear. If in doubt, compare the plug type and cable length with your original unit.

Fitting and support

Professional installation recommended. MJ Modifications offers fitting at our Warwickshire workshop. For a quote email info@mjmodifications.co.uk.

Compatibility check before dispatch

Order with confidence. We can verify fitment using your UK registration or the last 7 of your VIN. Add your vehicle details at checkout or email us for help.

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