{"id":510172,"date":"2022-07-13T10:13:03","date_gmt":"2022-07-13T16:13:03","guid":{"rendered":"https:\/\/cartreatments.com\/?p=510172"},"modified":"2022-11-07T09:41:57","modified_gmt":"2022-11-07T16:41:57","slug":"p0140","status":"publish","type":"post","link":"https:\/\/cartreatments.com\/p0140\/","title":{"rendered":"P0140 Code (Symptoms, Causes, and How to Fix)"},"content":{"rendered":"<p>When you start up your vehicle and start driving down the road the last thing you want to see is a check engine light. But for millions of drivers every year that\u2019s exactly what happens.<\/p>\n<p>Once you get your heart out of your throat and check the engine code, that only leads to a whole new list of problems you need to figure out. What does a code P0140 mean, how serious is it, and most importantly, how do you fix it?<\/p>\n<p>We\u2019ll break it all down for you here that way you get clear that engine code and get your vehicle back on the road and running like new. The good news is that a code P0140 isn\u2019t the downfall of your vehicle or your bank account balance!<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_39 counter-hierarchy ez-toc-counter ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" area-label=\"ez-toc-toggle-icon-1\"><label for=\"item-639b08545ed05\" aria-label=\"Table of Content\"><span style=\"display: flex;align-items: center;width: 35px;height: 30px;justify-content: center;direction:ltr;\"><svg style=\"fill: #23627c;color:#23627c\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #23627c;color:#23627c\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/label><input type=\"checkbox\" id=\"item-639b08545ed05\"><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-visibility-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/cartreatments.com\/p0140\/#What-Does-Code-P0140-Mean\" title=\"What Does Code P0140 Mean?\">What Does Code P0140 Mean?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/cartreatments.com\/p0140\/#Symptoms-of-Code-P0140\" title=\"Symptoms of Code P0140\">Symptoms of Code P0140<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/cartreatments.com\/p0140\/#Causes-of-Code-P0140\" title=\"Causes of Code P0140\">Causes of Code P0140<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/cartreatments.com\/p0140\/#Is-Code-P0140-Serious\" title=\"Is Code P0140 Serious?\">Is Code P0140 Serious?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/cartreatments.com\/p0140\/#How-to-Fix\" title=\"How to Fix\">How to Fix<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"What-Does-Code-P0140-Mean\"><\/span>What Does Code P0140 Mean?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<div class=\"su-box su-box-style-default\" id=\"\" style=\"border-color:#076b94;border-radius:3px\"><div class=\"su-box-title\" style=\"background-color:#3a9ec7;color:#FFFFFF;border-top-left-radius:1px;border-top-right-radius:1px\">OBD-II Trouble Code P0140 Description<\/div><div class=\"su-box-content su-u-clearfix su-u-trim\" style=\"border-bottom-left-radius:1px;border-bottom-right-radius:1px\"><strong>O2 Sensor Circuit \u2013 No Activity Detected<\/strong><\/div><\/div>\n<p>Your vehicle\u2019s oxygen sensors measure the number of harmful emission levels coming out of the exhaust system. There\u2019s an O2 sensor before the catalytic converter and one after the converter, and this tells the ECM how effective the catalytic converter currently is.<\/p>\n<p>However, if you have a code P0140 it\u2019s saying that right now the ECM isn\u2019t getting any signal from the oxygen sensor. It doesn\u2019t necessarily mean that the catalytic converter isn\u2019t working or that you have faulty oxygen sensors, only that it can\u2019t get any signal from those components.<\/p>\n<p>Because of this, your vehicle can\u2019t figure out if the system is working correctly or not, and that\u2019s why you\u2019re getting a check engine light.<\/p>\n<p><em>Related Codes: <a href=\"https:\/\/cartreatments.com\/p0134\/\">P0134<\/a>, <a href=\"https:\/\/cartreatments.com\/p0135\/\">P0135<\/a>, <a href=\"https:\/\/cartreatments.com\/p0136\/\">P0136<\/a>, <a href=\"https:\/\/cartreatments.com\/p0137\/\">P0137<\/a>, <a href=\"https:\/\/cartreatments.com\/p0138\/\">P0138<\/a>, <a href=\"https:\/\/cartreatments.com\/p0141\/\">P0141<\/a>, <a href=\"https:\/\/cartreatments.com\/p0154\/\">P0154<\/a>, <a href=\"https:\/\/cartreatments.com\/p0160\/\">P0160<\/a><\/em><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Symptoms-of-Code-P0140\"><\/span>Symptoms of Code P0140<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-508429\" src=\"https:\/\/cartreatments.com\/wp-content\/uploads\/failed-emissions-inspection.jpg\" alt=\"\" width=\"720\" height=\"405\" srcset=\"https:\/\/cartreatments.com\/wp-content\/uploads\/failed-emissions-inspection.jpg 720w, https:\/\/cartreatments.com\/wp-content\/uploads\/failed-emissions-inspection-200x112.jpg 200w, https:\/\/cartreatments.com\/wp-content\/uploads\/failed-emissions-inspection-100x56.jpg 100w, https:\/\/cartreatments.com\/wp-content\/uploads\/failed-emissions-inspection-213x120.jpg 213w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p>\n<p>If your vehicle has a code P0140 you\u2019ll have a check engine light, but chances are you won\u2019t have any other noticeable symptoms. The only time you\u2019ll notice a problem is when your vehicle goes in for an emissions test.<\/p>\n<p>Most emissions testers will automatically fail a vehicle with a check engine light from an emissions component. Since the oxygen sensor is part of the emissions system, it almost always leads to an automatic failure.<\/p>\n<p>Of course, without the rear oxygen sensor sending a signal to your ECM you might have raised NOx emission levels, and you might not even realize it. While this isn\u2019t a problem when it comes to performance, it is bad for the environment.<\/p>\n<ul>\n<li aria-level=\"1\">Check engine light<\/li>\n<li aria-level=\"1\">No abnormal symptoms<\/li>\n<li aria-level=\"1\"><a href=\"https:\/\/cartreatments.com\/failed-emissions-inspection\/\">Failed emissions test<\/a><\/li>\n<li aria-level=\"1\">Elevated NOx emissions<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Causes-of-Code-P0140\"><\/span>Causes of Code P0140<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>If you have a code P0140, there are really only two potential causes. The most likely problem is a faulty wiring or connection for the rear oxygen sensor. The problem could also be a <a href=\"https:\/\/cartreatments.com\/catalytic-converter-symptoms-and-replacement-cost\/\">defective catalytic converter<\/a>, but it is less likely than a wiring or connection issue.<\/p>\n<p>These wiring and connection issues can occur if a rock or another piece of road debris bounces up and hits the connector or wiring while you\u2019re driving. Another common cause is right after a mechanic or someone else completes work and they forget to plug the rear oxygen sensor back in.<\/p>\n<ul>\n<li aria-level=\"1\">Faulty wiring or connections to oxygen sensors<\/li>\n<li aria-level=\"1\">Defective catalytic converter<\/li>\n<\/ul>\n<h2><span class=\"ez-toc-section\" id=\"Is-Code-P0140-Serious\"><\/span>Is Code P0140 Serious?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><img decoding=\"async\" loading=\"lazy\" class=\"alignnone size-full wp-image-503340\" src=\"https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/01\/oxygen-sensor.jpg\" alt=\"oxygen sensor\" width=\"720\" height=\"354\" srcset=\"https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/01\/oxygen-sensor.jpg 720w, https:\/\/cartreatments.com\/wp-content\/uploads\/2019\/01\/oxygen-sensor-100x49.jpg 100w\" sizes=\"(max-width: 720px) 100vw, 720px\" \/><\/p>\n<p>While it\u2019s not a code you\u2019ll want to ignore, compared to most other check engine light codes a code P0140 isn\u2019t that serious. In fact, there\u2019s a good chance that everything is still operating exactly as it should.<\/p>\n<p>The real reason you need to fix a code P0140 is that you don\u2019t know for sure that everything is working the way it should. If another problem comes up with your vehicle, it has no way of telling you what\u2019s going on.<\/p>\n<p>Furthermore, there\u2019s nothing checking up on the oxygen sensors. So, if the catalytic converter or the oxygen sensor stops working you won\u2019t know. This means you could have elevated emissions and hotter than normal exhaust without even realizing it.<\/p>\n<p>Eventually, this can lead to the premature wear of different parts, but compared to other check engine lights, a code P0140 is about as mild as it gets.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"How-to-Fix\"><\/span>How to Fix<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>If you have a code P0140 it\u2019s common for inexperienced technicians to rush out and <a href=\"https:\/\/cartreatments.com\/bad-oxygen-sensor-symptoms-replacement-cost\/\">replace the O2 sensors.<\/a> Don\u2019t do it. Even if the oxygen sensors are doing everything they\u2019re supposed to, it can\u2019t get the reading from the oxygen sensor to the computer.<\/p>\n<p>That\u2019s because most of the time a P0140 comes from a faulty wiring connection. Double-check that you have everything plugged in and if your vehicle has any broken connectors.<\/p>\n<p>From there, check for power at the oxygen sensor. This will let you know what side of the problem the connection problem is on. Check out the wiring for breaks and the fuse if the issue is on the power side of things.<\/p>\n<p>If you have power at the connector the problem is between the oxygen sensor and the ECU, and it\u2019s most likely a break in the line. While the problem can be a faulty catalytic converter, this is a pretty rare occurrence.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>When you start up your vehicle and start driving down the road the last thing you want to see is a check engine light. But for millions of drivers every year that\u2019s exactly what happens. Once you get your heart &#8230; <a title=\"P0140 Code (Symptoms, Causes, and How to Fix)\" class=\"read-more\" href=\"https:\/\/cartreatments.com\/p0140\/\" aria-label=\"More on P0140 Code (Symptoms, Causes, and How to Fix)\">Read more<\/a><\/p>\n","protected":false},"author":1009,"featured_media":510173,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"no","_lmt_disable":"no"},"categories":[320],"tags":[249],"modified_by":"Mark Stevens","_links":{"self":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts\/510172"}],"collection":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/users\/1009"}],"replies":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/comments?post=510172"}],"version-history":[{"count":0,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/posts\/510172\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/media\/510173"}],"wp:attachment":[{"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/media?parent=510172"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/categories?post=510172"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cartreatments.com\/wp-json\/wp\/v2\/tags?post=510172"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}