2007 Runs Rough When Cold, Check Eng Light

[JohnDC]

Ok, our 2007 Liberty suddenly started running rough, misfiring when cold. After driving for 5 minutes or so it runs normally. The check engine light is on mostly steady, but flashed a few times. Also we got the "rotten egg" smell from the catalytic converter while it was running rough.
The funny thing is that it has been running fine. We went out for lunch yesterday, and the problem started when we left the restaurant.
I tired the key trick to get the codes, but no luck.
Any ideas?
Thanks, John

 

[Cardhu]

check your battery, KJ's do stupid things when the battery is on its way out.

I offer no explanation for the rotten egg smell.

 

[tommudd]

If the check engine light is on, there is an issue for sure.
get it checked to see what it is
I wouldn't just keep driving it without knowing
could be something as simple as a a sensor or something more serious
The rotten egg smell is a tell tale sign

 

[JohnDC]

Just got the codes read, it is a #4 cylinder misfire. Going to change the spark plugs first. Then wires.

 

[JohnDC]

Ok, so started to change the sparkplugs. I pulled the coil out from #4, and realized I need a longer extension to get to the spark plug. After many bad words were said, I put it back together, I started it up, and it ran perfectly. I still need to clear the check engine light, but it is idling smoother than it has in ages. I am going to change the wires and spray everything down with electrical cleaner, but very happy at the moment! I understand I can reset the check engine light by disconnecting the battery for 10 minutes?
Thanks,
John

 

[JohnDC]

check your battery, KJ's do stupid things when the battery is on its way out.

I offer no explanation for the rotten egg smell.

We just put a battery in it last month. In fact now it gives off 5 beeps when you turn it off, which it never used to do! I understand these trucks do have some aural alarm issues. :whymewhyme:

 

[tommudd]

Ok, so started to change the sparkplugs. I pulled the coil out from #4, and realized I need a longer extension to get to the spark plug. After many bad words were said, I put it back together, I started it up, and it ran perfectly. I still need to clear the check engine light, but it is idling smoother than it has in ages. I am going to change the wires and spray everything down with electrical cleaner, but very happy at the moment! I understand I can reset the check engine light by disconnecting the battery for 10 minutes?
Thanks,
John

So I assume you have the 4 cylinder then since you are going to change the wires?

 

[JohnDC]

So I assume you have the 4 cylinder then since you are going to change the wires?

No, I meant change the plugs, I dont know what I was thinking. :fca5278e:

 

[JohnDC]

For a final update, it is still running great, and the check engine light finally went out this morning. :signs1: