I have a 2007 jeep liberty limited, the engine light is on and idles rough, at around 60km/h it almost feels like the tranny is slipping or a misfire, I have replaced the plugs and am using a new coil pack to to swap each old one out one at a time to see if its just a bad coil, any ideas on what else it may be or where i should be looking.

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Moose

have you pulled any codes from it yet?
That would help see what it would be

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Welcome to LOST!

Pull the code, and report back.

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2012 Jeep Liberty KK 109k miles and stong
4" lift.
Gen 5.5 A-Arms
Maxxis 31x10.50x15
ATS42rle

I dont have a code reader, i will see if one of my buddies do and report back as soon as i can

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Moose

hey i finally was able to get the codes. P0300, P0306, P0038, P0138. and there are more issues now, like my tranny seems to be shifting hard going into 3 gear, auto tranny too, fuel mileage has gone down, still chugging at 60kmh,

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Moose

I'd help, but when you take months to reply with codes, your only hurting yourself... Good luck.

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2012 Jeep Liberty KK 109k miles and stong
4" lift.
Gen 5.5 A-Arms
Maxxis 31x10.50x15
ATS42rle

p0300 is random misfire, p0306 is misfire cyl 6, p0038 can be read here
http://www.engine-codes.com/codes.php?code=p0038_jeep

p0138 can be read here
http://www.engine-codes.com/p0138_jeep.html

In short. You can have a bad coil pack in cyl 6. Or you can have a bad cat on that side. You can also have some other exhaust restriction. What I would recommend is that you read up on these codes. Put your new coil pack on cyl 6. I suspect however that there is something going on in your exhaust system. A clogged catalytic converter can cause your symptoms, as can any other exhaust restriction.

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07 4x4 Sport/42RLE/2.5" Daystar lift/245/75/16 BFG KO2s on 16x8.5 Chaos 5 wheels. Did not have to hammer pinch welds....yet

I second the above.

However random cylinder misfire can also be caused by idiotically washing your engine. Done this myself.

The check for a clogged cat, use infrared to gun, or disconnect exhaust and see how it runs after.

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2004 KJ 3.7 Limited:
IRO WJ Upper Arm -- WJ Rear LCA's -- Rear Driveshaft Spacer -- JBA Upper A Arms -- 4 inch Lift -- 265/75/16 4" B/S -- WasherBottle Relocate -- Custom High Mount Intake -- Carpet Delete -- Homebrew Winch Bumper -- Warn VR8000 -- Homemade Plow -- Pinch Weld POUNDED -- POR 15 inner fenders --

sorry for it taking so long i went away on vacation and have been extremely busy with work since, this has been my first weekend off in 2 months. I thank those who have replied with tips. i have replaced the cyl 6 coil pack. and put new plugs on all around, its only been recently that my gas mileage went down, but my light has been on for awhile, would a back exhaust flow have a negative effect on how my tranny is shifting? i wouldnt think it would but im sure theres a way it could. i will have to replace my cat and probably both o2 sensors on that side and see what that fixes.

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Moose

You can check your 02 sensors with a 5 dollar volt meter. Check it out on youtube.. This can also tell you if you're cats are plugged.

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2004 KJ 3.7 Limited:
IRO WJ Upper Arm -- WJ Rear LCA's -- Rear Driveshaft Spacer -- JBA Upper A Arms -- 4 inch Lift -- 265/75/16 4" B/S -- WasherBottle Relocate -- Custom High Mount Intake -- Carpet Delete -- Homebrew Winch Bumper -- Warn VR8000 -- Homemade Plow -- Pinch Weld POUNDED -- POR 15 inner fenders --