{"product_id":"o2-oxygen-sensor-upstream-downstream-for-ford-fiesta-2011-2019-1-6l","title":"O2 Oxygen Sensor Upstream Downstream for Ford Fiesta (2011-2019) 1.6L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit O2 Sensor Kit for 2011-2019 Ford Fiesta (B299)\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e This matched upstream and downstream O2 sensor kit monitors pre- and post-catalyst exhaust oxygen on the 2011-2019 Ford Fiesta (\u003cstrong\u003eB299\u003c\/strong\u003e) \u003cstrong\u003e1.6L Ti-VCT Sigma\u003c\/strong\u003e for precise closed-loop fuel control.\u003c\/p\u003e\u003ch3\u003eThe Stock Ford Fiesta Oxygen Sensor Failure\u003c\/h3\u003e\u003cp\u003eFactory O2 sensors on the \u003cstrong\u003eB299\u003c\/strong\u003e Fiesta with the \u003cstrong\u003e1.6L Ti-VCT Sigma\u003c\/strong\u003e engine degrade from sustained exhaust heat cycling, carbon fouling, and moisture contamination. Over time, internal zirconia ceramic elements crack and internal heater circuits burn out, causing sluggish voltage switching. These failures skew short- and long-term PCM fuel trims and trigger \u003cstrong\u003eP0130\u003c\/strong\u003e, \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, or false \u003cstrong\u003eP0420\u003c\/strong\u003e catalyst codes.\u003c\/p\u003e\u003ch4\u003eCommon Symptoms of a Failing OEM O2 Sensor\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eCEL \u0026amp; Heater DTCs:\u003c\/strong\u003e Stored codes like \u003cstrong\u003eP0135\u003c\/strong\u003e, \u003cstrong\u003eP0141\u003c\/strong\u003e, \u003cstrong\u003eP0130\u003c\/strong\u003e, or \u003cstrong\u003eP0171\u003c\/strong\u003e from open heaters or slow switching.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRough Idle \u0026amp; Hesitation:\u003c\/strong\u003e Skewed upstream air-fuel feedback disrupts closed-loop fueling under load.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFailed Emissions \u0026amp; Low MPG:\u003c\/strong\u003e Rich fuel trims foul spark plugs and drop fuel economy.\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eThe Direct-Fit Heated Zirconia Oxygen Sensor Solution\u003c\/h3\u003e\u003cp\u003eReplacing both sensors as a matched set restores factory response across the \u003cstrong\u003e1.6L Ti-VCT Sigma\u003c\/strong\u003e exhaust stream. Each unit features a laser-welded stainless housing, high-temperature zirconia ceramic element, and calibrated internal heater matching OEM specs for \u003cstrong\u003eAE8Z9F472A\u003c\/strong\u003e, \u003cstrong\u003eAE8Z9F472B\u003c\/strong\u003e, \u003cstrong\u003eAE8Z9G444B\u003c\/strong\u003e, and \u003cstrong\u003eAE8Z9G444C\u003c\/strong\u003e. Factory-style connectors and OEM-length harnesses bolt directly into stock bungs with zero wiring splicing.\u003c\/p\u003e\u003ch3\u003eWhat's Included\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e1 Upstream Oxygen Sensor (\u003cstrong\u003e234-4493\u003c\/strong\u003e)\u003c\/li\u003e\n\u003cli\u003e1 Downstream Oxygen Sensor (\u003cstrong\u003e234-4555\u003c\/strong\u003e)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e2011-2019 Ford Fiesta\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e1.6L Ti-VCT Sigma \/ B299\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEmissions \u0026amp; Substrate\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eHeated Zirconia Ceramic \/ Direct-Fit Upstream \u0026amp; Downstream\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eInstallation Type\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003eDirect Bolt-On OEM Replacement (No Cutting or Welding)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e234-4493, 234-4555, AE8Z9F472A, AE8Z9F472B, AE8Z9G444B, AE8Z9G444C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003c\/div\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e2011-2019 Ford Fiesta 1.6L (Confirm engine before ordering)\u003c\/li\u003e\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions \u0026amp; Fitment Warnings\u003c\/h3\u003e\u003ch4\u003eDoes this fit the B299 Fiesta?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Direct fit for the 2011-2019 Ford Fiesta equipped with the \u003cstrong\u003e1.6L Ti-VCT Sigma\u003c\/strong\u003e engine. \u003cstrong\u003eConfirm engine before ordering; excludes 1.6L EcoBoost ST and 1.0L EcoBoost models.\u003c\/strong\u003e\u003c\/p\u003e\u003ch4\u003eWill this clear P0135, P0141, or P0420 codes?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes, if sensors are faulty.\u003c\/strong\u003e New \u003cstrong\u003e234-4493\u003c\/strong\u003e and \u003cstrong\u003e234-4555\u003c\/strong\u003e units restore heater resistance and switching speed; inspect for exhaust leaks before clearing \u003cstrong\u003eP0420\u003c\/strong\u003e.\u003c\/p\u003e\u003ch4\u003eAre the harnesses plug-and-play?\u003c\/h4\u003e\u003cp\u003e\u003cstrong\u003eYes.\u003c\/strong\u003e Factory-matched connectors and OEM lead lengths install directly into \u003cstrong\u003eB299\u003c\/strong\u003e exhaust bungs with zero splicing.\u003c\/p\u003e\u003ch3\u003eThe Ford Precision Standard\u003c\/h3\u003e\u003cp\u003eAccurate O2 feedback keeps ECU fuel mapping sharp and emissions-compliant across daily operation. Matched upstream and downstream sensors restore CEL-free reliability on the \u003cstrong\u003eB299\u003c\/strong\u003e platform.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":68094243832056,"sku":"DS-E7F6QQ7CJ","price":45.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/o2-oxygen-sensor-upstream-downstream-for-ford-fiesta-2011-2019-1-6l-1.jpg?v=1794618332","url":"https:\/\/performancechiptuning.com\/fr\/products\/o2-oxygen-sensor-upstream-downstream-for-ford-fiesta-2011-2019-1-6l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}