# Misfiring badly on three cylinders

**URL:** <https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848>\
**Category:** Maintenance/Repairs\
**Tags:** liberty, jeep\
**Created:** [October 5, 2020, 2:35pm UTC](https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848 "2020-10-05T14:35:24Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ozarkcavefish](https://avatars.discourse-cdn.com/v4/letter/o/2bfe46/32.png) [@ozarkcavefish](https://community.cartalk.com/u/ozarkcavefish)\
**Post date:** [October 5, 2020, 2:35pm UTC](https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848/1 "2020-10-05T14:35:24Z")

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I have a 2003 Jeep liberty with about 195,000 miles on it.

All of a sudden it’s misfiring pretty badly. I was able to park it for a few minutes the other day and drive home 40 miles normally, but the next day it didn’t seem driveable at all.

There’s a small evap leak code and a random misfire code. Also, misfire codes for cylinders 4 5 and 6, which would be different sides of the engine.

I’m not sure of the evap code could be related or not. I’m thinking that faulty fuel injectors / plugs / ignition coils sound unlikely because it’s multiple cylinders all of a sudden? Compression-related problems sounds more unlikely to me because it’s multiple cylinders on multiple banks.

My best idea is a failing fuel pump, although I don’t presently have a pressure gauge.

Any ideas?

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**Author:** ![Rod-Knox](https://avatars.discourse-cdn.com/v4/letter/r/a183cd/32.png) [@Rod-Knox](https://community.cartalk.com/u/Rod-Knox)\
**Post date:** [October 5, 2020, 2:46pm UTC](https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848/2 "2020-10-05T14:46:42Z")

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If a SWAG will get you started look for a leaking upper intake.

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**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\
**Post date:** [October 7, 2020, 2:37am UTC](https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848/3 "2020-10-07T02:37:47Z")

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I believe the Jeep Liberty was well known for having top end . . . as in cylinder head . . . problems

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**Author:** ![Cavell](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/cavell/32/43396_2.png) [@Cavell](https://community.cartalk.com/u/Cavell)\
**Post date:** [October 7, 2020, 9:08pm UTC](https://community.cartalk.com/t/misfiring-badly-on-three-cylinders/170848/4 "2020-10-07T21:08:24Z")

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V6 I assume? Intake manifold could be issue. Is it plastic intake or cast alum? Does it have a single coil pack? Or is it COP?