# 03 Avalanche misfire?

**URL:** <https://community.cartalk.com/t/03-avalanche-misfire/64095>\
**Category:** Maintenance/Repairs\
**Tags:** chevrolet, avalanche\
**Created:** [April 26, 2011, 4:27pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095 "2011-04-26T16:27:11Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![tomhhh](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tomhhh/32/1667_2.png) [@tomhhh](https://community.cartalk.com/u/tomhhh)\
**Post date:** [April 26, 2011, 4:27pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/1 "2011-04-26T16:27:11Z")

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My 03 Chev Avalanche is giving me a P0300 code (multiple or random misfire). With no distributor or individual coil is this something I can fix myself or is it shop time?

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [April 26, 2011, 4:40pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/2 "2011-04-26T16:40:56Z")

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You can probably replace the plugs and wires yourself. The plugs are due at 100K. And yes you have CNP (coil near plug) ignition, so you have eight coils.

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**Author:** ![tomhhh](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tomhhh/32/1667_2.png) [@tomhhh](https://community.cartalk.com/u/tomhhh)\
**Post date:** [April 26, 2011, 7:06pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/3 "2011-04-26T19:06:23Z")

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This came on suddenly. Does this point to a ECM problem?

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**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\
**Post date:** [April 26, 2011, 7:52pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/4 "2011-04-26T19:52:37Z")

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My guess would be a failing crankshaft position sensor or a faulty connection at the sensor plug.

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**Author:** ![system](https://global.discourse-cdn.com/cartalk/original/3X/1/d/1d47c66a543aa6c5a7873bb2320858f978ff52ed.png) [@system](https://community.cartalk.com/u/system)\
**Post date:** [April 26, 2011, 9:13pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/5 "2011-04-26T21:13:50Z")

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Most likely not. Change those plugs, see what happens. I certainly wouldn’t wait until 100k to do it.

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**Author:** ![common-sense-answer](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/common-sense-answer/32/716_2.png) [@common-sense-answer](https://community.cartalk.com/u/common-sense-answer)\
**Post date:** [April 26, 2011, 9:32pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/6 "2011-04-26T21:32:06Z")

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Find The Main Engine Wiring Harness Ground Wire Where It Attaches With A Nut Or Bolt To A Cylinder Head (I Believe The Right Head) And Make Sure It’s Not Corroded.

This wire grounds the ECM and some have been found to rust / corrode and set misfire DTCs. If it’s not clean then remove it, clean it, and reinstall it.

CSA

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**Author:** ![cigroller](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@cigroller](https://community.cartalk.com/u/cigroller)\
**Post date:** [April 26, 2011, 10:01pm UTC](https://community.cartalk.com/t/03-avalanche-misfire/64095/7 "2011-04-26T22:01:08Z")

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I would also stick a fuel pressure gauge on it.