{"product_id":"acdelco-gm-original-equipment-213-3521-ignition-knock-sensor-oem-fit","title":"ACDelco GM Original Equipment 213-3521 Ignition Knock Sensor - OEM Fit","description":"\u003cp\u003eIn this review of the ACDelco GM Original Equipment 213-3521 Ignition Knock (Detonation) Sensor, the bottom line is simple: this is the replacement to choose if you need a direct-fit, GM-recommended sensor that restores proper knock detection and timing control. The reviewer found it especially useful for owners of GM vehicles looking for an exact factory-style part; its primary benefit is reliable signals to the engine control module that let the vehicle correct ignition timing and help prevent engine damage from pre-ignition. Ease of installation and consistent fit are emphasized throughout this review.\u003c\/p\u003e\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul\u003e\n \u003cli\u003e\n\u003cstrong\u003eSends signals to the ECM:\u003c\/strong\u003e Produces a voltage signal based on engine vibrations so the engine control module can adjust ignition timing and air\/fuel mixture.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003ePrevents engine damage:\u003c\/strong\u003e Detects pinging or spark knock early, helping to prevent damage caused by pre-ignition when the ECM retards timing.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eGM-recommended replacement:\u003c\/strong\u003e Supplied as a recommended replacement for your vehicle's original factory component to preserve intended engine performance.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eOE quality and durability:\u003c\/strong\u003e Manufactured to GM original equipment specification to match the performance and service life expected from General Motors parts.\u003c\/li\u003e\n \u003cli\u003e\n\u003cstrong\u003eFit, form, and function:\u003c\/strong\u003e Built to the same fit and mounting characteristics as the original sensor to simplify direct replacement without modification.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eWho It's For\u003c\/h2\u003e\n\u003cp\u003eThis sensor is aimed at GM owners, mechanics, and DIY enthusiasts who need a dependable, direct-replacement knock sensor that matches factory specifications and fitment. It is particularly well suited for those repairing vehicles where the original sensor triggered a check engine light or where timing corrections are needed to resolve spark knock.\u003c\/p\u003e\n\u003cp\u003eIt is less relevant for non-GM vehicles or projects that require universal or performance-tuned knock sensing solutions; those users should look for aftermarket sensors designed for custom installations or adjustable thresholds.\u003c\/p\u003e\n\u003ch2\u003ePros \u0026amp; Cons\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003ePros\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003eDirect-fit OEM construction ensures easy installation and proper alignment with factory wiring and mounting.\u003c\/li\u003e\n \u003cli\u003eCustomers report solid \u003cstrong\u003efunctionality\u003c\/strong\u003e and reliable fit on compatible engines, reducing installation time and hassle.\u003c\/li\u003e\n \u003cli\u003eManufactured to GM specification, offering the expected \u003cstrong\u003equality\u003c\/strong\u003e and durability of original equipment components.\u003c\/li\u003e\n \u003cli\u003eGenerally regarded as good \u003cstrong\u003evalue for money\u003c\/strong\u003e compared with replacing other engine parts caused by unchecked detonation.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eCons\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n \u003cli\u003eSome customers report mixed results with the check engine light and code return, meaning additional diagnosis may be required if codes persist.\u003c\/li\u003e\n \u003cli\u003eNot suitable for non-GM vehicles or custom engine management applications without modification.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003ctable\u003e\n \u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eACDelco\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eModel\u003c\/td\u003e\n\u003ctd\u003e213-3521\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eIgnition Knock (Detonation) Sensor\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eApplication\u003c\/td\u003e\n\u003ctd\u003eGM-recommended replacement for original factory component\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eSends vibration-based voltage signal to ECM to adjust timing\u003c\/td\u003e\n\u003c\/tr\u003e\n \u003ctr\u003e\n\u003ctd\u003eManufacturing Standard\u003c\/td\u003e\n\u003ctd\u003eBuilt to GM original equipment specification for fit, form, and function\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch2\u003eOur Verdict\u003c\/h2\u003e\n\u003cp\u003eThe ACDelco 213-3521 is a sensible choice for GM vehicle owners who need a trustworthy, factory-equivalent knock sensor that fits and functions like the original. It offers durable OEM construction and straightforward installation, making it a good value for those repairing knock-related codes or restoring proper timing control, though persistent codes may require further diagnostics.\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWill this sensor fit my GM vehicle?\u003c\/strong\u003e\u003cbr\u003eIt is manufactured as a GM-recommended replacement and is intended to match original factory fitment; verify vehicle compatibility before purchase.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWill replacing the sensor clear a check engine light?\u003c\/strong\u003e\u003cbr\u003eMany users report the check engine light clears after replacement, but some experienced mixed results, so additional diagnostics may be needed if codes return.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eIs this an OEM-quality part?\u003c\/strong\u003e\u003cbr\u003eYes, it is produced to GM original equipment specification for the same fit, form, and function as the factory component.\u003c\/p\u003e","brand":"ACDelco","offers":[{"title":"Default Title","offer_id":48257197474011,"sku":"B000K02EDG","price":57.78,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0724\/1043\/1707\/files\/71Ujkyq_BeL._AC_SL1500.jpg?v=1778297560","url":"https:\/\/gearmusthave.com\/products\/acdelco-gm-original-equipment-213-3521-ignition-knock-sensor-oem-fit","provider":"GearMustHave","version":"1.0","type":"link"}