2003 jeep liberty 4x4 v6 P0354 D code

[John Lovett]

Hello everyone,
I'm new to this site & by no means a mechanic But I do own a 03 jeep liberty that I wrench on a little. Yesterday it codes P0354 D , coil pack at about 185,500 miles. It had a hard miss but no knocks or pings. I replaced all 6 coil packs as well as all 6 spark plugs. When I completed installing new parts, I crank it up & it still had a less pronounced miss, but still there. I went to auto zone & had them pull the code & it pulled the same P0354 D code even after new packs & plugs installed. Has anyone else in jeep land experienced this issue & corrective measures taken to correct this?

Again, I'm new to forum & by no means a mechanic. Thank you in advance for any constructive feedback & guidance on this issue.

 

[tommudd]

Several things can cause issues like that
I assume that you used good coil packs and NGK copper plugs ....................
But also could be
Faulty or corroded wiring on coil pack
Faulty ignition coil(s)
Faulty spark plug(s)
Faulty idle air control valve or electronic body
Damaged or corrosion in the wiring that connects coil pack to the PCM
Open or short in the wiring or electrical circuit of second cylinder coil pack
Carbon buildup causing blockage in the Throttle Body air passages
Intake manifold vacuum leaks

 

[John Lovett]

Several things can cause issues like that
I assume that you used good coil packs and NGK copper plugs ....................
But also could be
Faulty or corroded wiring on coil pack
Faulty ignition coil(s)
Faulty spark plug(s)
Faulty idle air control valve or electronic body
Damaged or corrosion in the wiring that connects coil pack to the PCM
Open or short in the wiring or electrical circuit of second cylinder coil pack
Carbon buildup causing blockage in the Throttle Body air passages
Intake manifold vacuum leaks

Thanks for the reply. Yes brand new duralast coil packs & brand new ngk copper plugs. It appears I've got my work cut out for me.

 

[Billwill]

Disconnect the battery and re-plug the connectors on the PCM a few times....there may be a bad connection for Coil Pack #4.

You can download the 2003 Jeep KJ Service manual here..section 8W has the Wiring Diagrams.

Check the wiring for Coil Pack #4 is not scraping to engine/chassis somewhere.
How does Plug #4 look if you inspect it....any water/oil/gunge on it?

www.colorado4wheel.com/manuals/Jeep/KJ/

 

[John Lovett]

Disconnect the battery and re-plug the connectors on the PCM a few times....there may be a bad connection for Coil Pack #4.

You can download the 2003 Jeep KJ Service manual here..section 8W has the Wiring Diagrams.

Check the wiring for Coil Pack #4 is not scraping to engine/chassis somewhere.
How does Plug #4 look if you inspect it....any water/oil/gunge on it?

www.colorado4wheel.com/manuals/Jeep/KJ/

Billwill thanks for the reply. Overall the wiring looks good. The plugs were all extremely snug & free of any cracks or damage. I will try the plug on the pcm. Also no dirt or oil up in the plug housing that connects to coil pack. Thanks.