Got the Lean Cylinder code - how should I approach this?

[catfishhands]

I have a 96’ LX with 163k that is new to me as of a week ago. No maintenance records. Code P0301 is showing. I cleared it when I got it and have driven about 50 miles and it is now back.

My concern is other people have a cylinder go lean and it isn’t ignition related but rather head gasket troubles.

Should I start replacing ignition sh1t? Or go ahead and get the to a brothel and replace the head gasket?

Thanks

 

[Tools R Us]

First why is it missing, fuel, spark, oil or coolant fowling?

 

[catfishhands]

Let me go pull the spark plug in #1 and get a look see.

@Tools R Us any tips on differentiating what is what of those three?

Thanks again

 

[catfishhands]

Here’s no. 1

 

[Malleus]

You electrode should have a slight grayish powder on it. This is normal combustion residue.

Your electrode, from what I can see, looks OK. Also looks like you have the same problem I have, your plug wire seals are shot.

I wouldn't start throwing parts at it, unless you really want a new truck. Don't assume that the problem is related to a cause without evidence. Walk through the fault tree and you'll find the problem.

The fault tree:

 

[Malleus]

FSM wisdom (such as it is)

 

[catfishhands]

Thank you! Will update as I know more.

 

[ThomasMore66]

Just had an issue with lean out on my 94. Turned out to be a tank of bad gas that killed the fuel filter and one injector. I’d check that fuel filter. Just me.

 

[catfishhands]

Thanks @ThomasMore66 will look into it.

Also, DOES THIS HELP ANYTHING?!

 

[Malleus]

Rodent entry, other than that, no. Duct tape will work in a pinch. It won't look pretty, but that hose is kinda needed.

 

[ewillis]

Where’s @nukegoat when you need him?

 

[catfishhands]

Okay so I got a multimeter but ran out of light before I could test the injectors. BUT. I took a screen capture of both of my cruisers running. It was about 45 degrees and I assumed the vapor from the exhaust was just that, temperature related. Then I started my tundra and it had zero exhaust, then I started my other cruiser and it had zero vapor or smoke. But the FZJ had a s*** ton of white vapor/smoke emitting from the exhaust. Here is a shot from the video I can’t upload.

 

[bajaphile]

Probably condensation. If it is coolant it is an obvious smell.

 

[catfishhands]

It stayed blowing that out for 30 minutes

 

[ThomasMore66]

Hmm. Head gasket?

 

[Qball]

Thanks @ThomasMore66 will look into it.

Also, DOES THIS HELP ANYTHING?!

View attachment 1576648

Bingo! That will give you lean error codes every time!

 

[bugsnbikes]

did u look under the oil fill cap for milky goo?

 

[bugsnbikes]

or drain oil and let everything settle a while and look for water/coolant floating on top?

 

[White Stripe]

How does your Coolant level look? Have you had to add any?

 

[bigredmachine]

whats the date code on your plug wires, if their factory wires they will a manufacture date on the wire to give you an idea of how old they are