P0301 code after new spark plugs

PhillyJake

PhillyJake

TJ Enthusiast
Joined
Sep 22, 2020
Messages
106
Location
Philadelphia
Hi Friends - got a little thing happening. Two nights ago I replaced both downstream o2 sensors (PO used Bosch, I swapped them for NGKs) b/c I was throwing a P0161 code. Took less than 15 minutes and it was humming: No more CEL, running a little smoother, like a brand new 04 Rubicon w/ 180,000 miles.

Today I did the spark plugs (Autolites up and down), and then fired it up. Tick, tick tick...not sure what that constant, rhythmic ticking is, but I assumed it was the fan shroud since it's loose. Shut her down and then did a Sea Foam treatment into the throttle body until it smoked. Shut her down, let her sit, fired her back up...the ticking is back. I took her out for a spin, CEL light on, and now I'm chasing a P0131 code.

I looked through this thread on the dreaded code, but naturally, nothing quite lined up with my personal and unique experience. So, a couple questions:
  • this started after the spark plugs, but before the sea foam, so I'm assuming I did something wrong with the spark plugs (it was my first time doing spark plugs) - perhaps my cylinder one spark plug is bad out of the box? Or I need to adjust the gap?
  • I'm assuming "cylinder one" refers to the frist spark plug at the front of the jeep - rather than the firing order...is that right?
  • As a novice mechanic, I'd like to be able to tackle this on my own, but I also don't want to, I don't know, blow up the Jeep
Open to ideas, or at least, first steps on what I should try first before I panic-call my mechanic. Thanks in advance!
 
phacor8 said:
Which autolites did you use?
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Jerry Bransford said:
X2, exactly what model plug did you install?
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I did a little digging through the forum and decided to get these from Amazon: Autolite XP985-4PK Iridium XP Spark Plug
sparkplugs.jpgshould I have used something else?
Wtrask said:
Check your work
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JKP said:
Be sure the coil is properly seated on the plugs and that the springs are in the boots. An arc will tic.
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This was a suspicion of mine...I wonder if I seated the plugs improperly. I didn't cross-thread anything, but I'll have to go back and check that everything is connected and contacting the way it's supposed to be. Is there anything specifical I should be looking for? I appreciate the coil guidance but want to make sure I'm thinking in the right direction: the coil is the single rail component that runs across the plugs and bolts over top of them, correct? And I didn't realize there are supposed to be springs in the boots? I'll see if I can find a picture to understand what that should look like, but if anyone has a pic laying around they can post, that would be awesome.

My spidey sense is telling me that either I mucked up the reinstall, or may have inadvertently misplaced a piece - which is just another way to say that I mucked things up. Either way, I'll dive back in tomorrow to gauge how bad I mucked. Hope I didn't install a plug upside down...

Thanks, all, for the time and guidance - it is why I love this forum, this community, and my Jeep!
 
Ok so here’s what I’ve found so far: all springs seem to be in the plug boots, so I think we’re good there. I took all the plugs out, cleaned them, checked the gap (0.35”), and replaced them, hand tightening them down. I switch plug 1 with plug 6 (in sequence from front to back).

No evidence on any of the plugs of cross threading, but I can only hand tighten plug 1 (first at front of Jeep) approx 2 turns before it sticks - all the others (incl swapped 6 at firewall) went all the way down. I gave it a few turns with the wrench then pulled it back out. Threads appear ok. I also cleaned out a fair amount of rust flakes from the plug hole with a small shop vac.

Question: I’m wondering if I should tighten down the plug or if it’s too much of a risk of cross threading this puppy. Thoughts?
 
Fixed! I think.

Spent a couple hours going back through my work and meticulously redoing it…much to my wife’s displeasure.

I swapped the first and lay plugs but was still having trouble hand tightening the first plug. So I went out and got a spark plug thread chaser and cleaned out the first plug hole. Then I slowly reinstalled the rail and made sure all the boots were seated correctly. Despite paying close attention, I still missed two boots that I only saw after I was getting ready to bolt down the rail. Finally, with everything installed, I fired the old girl up and she seems to be running smoothly!

Moral of the story: take your time and do it right the first time so you don’t have to do it a second time.
 
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Terry from Texas said:
P0131 is an O2 Sensor code and P0301 is a Cyl 1 miss. Your title says 0301 and in the body of message says 0131???
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see the problem here is I can't type and have no attention to detail.

Hence the root of my problem throwing codes: I went back and it turns out my work was shoddy, the rail wasn't installed correctly, and I needed to tighten things down.

Moral of the story: check your work. And can somebody check my work?
 
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PhillyJake said:
see the problem here is I can't type and have no attention to detail.

Hence the root of my problem throwing codes: I went back and it turns out my work was shoddy, the rail wasn't installed correctly, and I needed to tighten things down.

Moral of the story: check your work. And can somebody check my work?
Click to expand...
i like this guy
 
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