{"nhtsa_id":603139,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1999-02-03","date":"1998-12-18","document_id":"184498","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL","mfr_system":null,"summary":"SOME VEHICLES MAY EXHIBIT A SAG/ HESITATION FOLLOWING A COLD ENGINE START OR PARTIAL COOL DOWN RE-START, COULD BE CAUSED BY THE OXYGEN SENSOR ENTERING CLOSED LOOP PREMATURELY/IS EXPERIENCED WITHIN FIRST 30-40 SECONDS INTO THE DRIVE CYCLE. *AK","document":null,"url":"https://open.wenmarpro.com/bulletins/603139","components":[{"id":"engine","name":"Engine","parent":null},{"id":"exhaust-emissions","name":"Exhaust and emissions","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"JEEP","model":"GRAND CHEROKEE","year_from":1999,"year_to":1999,"match":"exact","vehicle_ids":["1999_jeep_grand-cherokee"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}