{"id":79529,"date":"2022-08-16T09:59:20","date_gmt":"2022-08-16T16:59:20","guid":{"rendered":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/?p=79529"},"modified":"2022-08-16T09:59:20","modified_gmt":"2022-08-16T16:59:20","slug":"2003-silverado-5-3l-3rd-gen-ls1-code-p0300","status":"publish","type":"post","link":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/2022\/08\/2003-silverado-5-3l-3rd-gen-ls1-code-p0300","title":{"rendered":"2003 Silverado 5.3L 3rd gen. LS1 Code P0300"},"content":{"rendered":"\n

I accidentally drove my Chevy truck<\/a> in low 3rd gear at 65 mph for about 8 min. or 5 miles. The truck slowly bogged down and I limped back home. Since then, I cannot seem to get things back to normal. Before this happened, I had everything running great. It seems like a fuel problem. I can start the engine but it idles very rough and I can get it up to 3000rpm but after about 30sec, It looses power and decelerates. Had several DTC codes but the one I cannot get rid of is PO300 (random misfire) and even though I replaced the MAF, I still get an occasional PO101 code. I replaced the MAP, MAF and since It has 185000mi, I also replaced the oil pump, timing chain and water pump. I still have same symptoms. And I have reset the computer and cleaned the throttle body. I have not attempted to do anything to the throttle control yet. I have 62psi fuel pressure at the rail and I have tested the fuel regulator and checked for air intake leaks. Can you help? would the transmission solenoids make it run badly in idle? Since I drove it the way I did, I was looking for mechanical problems but I see none.<\/p>\n\n\n\n

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First thought, intake gasket. <\/p>\n\n\n\n

Though the cause of the problem may or may not be the intake manifold gasket I still am leaning toward a vacuum leak of some kind. Since you have a p0300 misfire code<\/a> it also falls in that category. But lets get you the technical information so we don’t leave anything. <\/p>\n\n\n\n

Chevy Code P0300 <\/h2>\n\n\n\n
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I accidentally drove my Chevy truck in low 3rd gear at 65 mph for about 8 min. or 5 miles. The truck slowly bogged down and I limped back home. Since then, I cannot seem to get things back to normal. Before this happened, I had everything running great. It seems like a fuel problem.… Read More »2003 Silverado 5.3L 3rd gen. LS1 Code P0300<\/span><\/a><\/p>\n","protected":false},"author":17359,"featured_media":33418,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[1,3],"tags":[],"class_list":["post-79529","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-auto-repair-questions","category-chevy"],"_links":{"self":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts\/79529","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/users\/17359"}],"replies":[{"embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/comments?post=79529"}],"version-history":[{"count":0,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/posts\/79529\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/media\/33418"}],"wp:attachment":[{"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/media?parent=79529"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/categories?post=79529"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.freeautomechanic.com\/mechanic\/forum\/wp-json\/wp\/v2\/tags?post=79529"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}