PULLING MY HAIR OVER A P0301 code!!

[CrashTestDummy]

Finish replacing the plugs, AND, I'd recommend, a fresh set of plug wires. Our '12 Caprice developed a miss, and after swapping things around and not getting resolution, I threw a fresh set of AC plugs and Delco wires on it. All the codes cleared. This is the first 'modern' car we've owned where plugs/wires would cause a miss, and a fresh set of both actually fixed the issue.

All of the plugs came out looking used, but clean and with good color. The plugs you show in the attachments above look like cr@p!

 

[RET423]

My 2 cents
Your misfire turns off the stabilitrack when it occurs

Your misfire wasn't properly diagnosed

Always move a coil pack to see if the miss moves with the coil pack, if it doesn't leave the coil packs alone

Do the same with the spark plug and wire unless there is something obviously bad, see if the miss moves

If the miss moves you have found the problem & know what to buy, if the miss didn't move, move the injector next & see if the miss moves

If not your problem is in the cylinder and you haven't spent any money yet

Now you check compression but with the white smoke I think your going to have a blown head gasket

 

[dkad260]

That spark plug is terrible looking, no chance on earth it's going to fire. I would definitely perform a compression test on at least Cyl 1&3, then 2&4....and compare.

Do you have a restricted PCV system, maybe a catch can that's clogged?

I agree the white smoke is not a good sign. What does the dipstick look like? Hopefully just oil and not a milkshake.

 

[PBandJs_PPV]

That spark plug is terrible looking, no chance on earth it's going to fire. I would definitely perform a compression test on at least Cyl 1&3, then 2&4....and compare.

Do you have a restricted PCV system, maybe a catch can that's clogged?

I agree the white smoke is not a good sign. What does the dipstick look like? Hopefully just oil and not a milkshake.

This whole thing has me regretting buying this PPV. I've never had a simple misfire not be fixed with a plug alone, in some cases the wire, and in rare cases the coil.

It's chewing through gas like it was free. I can't seem to locate the cause of the misfire. It smells HEAVILY of raw fuel and shakes like it's going through withdrawals.

Here are new details I have. The codes are now:
P0301 misfire #1 cylinder
P0446 EVAP System Vent Control
P0461 Fuel Level Sensor "A" Circuit Range/Performance
P0463 Fuel Sensor "A" Circuit High

The odd thing is that looking at recorded 'live' data from the OBD scanner, I'm not seeing a misfire on #1, but I am seeing misfires on 2, 3, 5, and 7. Sometimes 3. All plugs and wires have been changed on 1, 3, 5, 7, and 2. (NGK G-Power plugs and generic 10.5mm silicone wires)

I cleared the codes, restarted the truck and THE SECOND the CEL comes on, I hear a noise coming from the rear of the truck (thinking it might be the Canister Purge Valve making that whine.) I'm not sure at this point. It is a kind of hum. I can re-create it by clearing the codes and starting the truck up again and waiting less than 30 seconds.

I have also begun to think that it might be a clogged PCV system that is causing the misfire, along with perhaps the Canister Purge Solenoid under the hood.
What do y'all think?? Could it be a partially clogged fuel filter?

I don't want to just throw a flurry of parts at this, but I'm getting desperate enough to start just throwing parts at this thing. And the 'coincidental' fuel gauge failure isn't helping as my wife is having to still drive this thing 30 miles a day to/from work and I troubleshoot once It's cooled down.

When I checked the oil level a couple of weeks ago before this all began, it was just oil, no milkshake.

I also put about 1.5 cups worth of acetone in the tank to 'superclean' the injectors.

 

[PBandJs_PPV]

Finish replacing the plugs, AND, I'd recommend, a fresh set of plug wires. Our '12 Caprice developed a miss, and after swapping things around and not getting resolution, I threw a fresh set of AC plugs and Delco wires on it. All the codes cleared. This is the first 'modern' car we've owned where plugs/wires would cause a miss, and a fresh set of both actually fixed the issue.

All of the plugs came out looking used, but clean and with good color. The plugs you show in the attachments above look like cr@p!

Is using Delco wires recommended? I know plugs can be pretty specific to an engine but wires?

 

[Fless]

P0446 EVAP System Vent Control

I cleared the codes, restarted the truck and THE SECOND the CEL comes on, I hear a noise coming from the rear of the truck (thinking it might be the Canister Purge Valve making that whine.) I'm not sure at this point. It is a kind of hum. I can re-create it by clearing the codes and starting the truck up again and waiting less than 30 seconds.

The evap valve at the rear is the canister VENT valve. The purge valve is in the engine compartment.

Have you looked at fuel trims? If not, take a look at them and post 'em up.

You may want to consider doing the TSB that includes the updated valve cover; maybe @donjetman can point us to what he did.

 

[PBandJs_PPV]

The evap valve at the rear is the canister VENT valve. The purge valve is in the engine compartment.

Have you looked at fuel trims? If not, take a look at them and post 'em up.

You may want to consider doing the TSB that includes the updated valve cover; maybe @donjetman can point us to what he did.

Okay, thank you, yes. I believe the noise is coming from the vent valve. If I had to say, the sound is like a slight suction leak, sort of...

I have historical 'recorded' data. I can post:
Long term fuel % trim - Bank 1
Long term fuel % trim - Bank 2
Oxygen sensor 1 Bank 1 Short term fuel trim (Does not show any data)
Oxygen sensor 1 Bank 2 Short term fuel trim (Does not show any data)
Short term fuel % trim - Bank 1
Short term fuel % trim - Bank 2

Which of these would be helpful?

I have read the TSB info posted by donjetman and fully plan to swap the valve covers ASAP, but I need to locate and address the misfire first.

 

[Fless]

Okay, thank you, yes. I believe the noise is coming from the vent valve. If I had to say, the sound is like a slight suction leak, sort of...

I have historical 'recorded' data. I can post:
Long term fuel % trim - Bank 1
Long term fuel % trim - Bank 2
Oxygen sensor 1 Bank 1 Short term fuel trim (Does not show any data)
Oxygen sensor 1 Bank 2 Short term fuel trim (Does not show any data)
Short term fuel % trim - Bank 1
Short term fuel % trim - Bank 2

Which of these would be helpful?

I have read the TSB info posted by donjetman and fully plan to swap the valve covers ASAP, but I need to locate and address the misfire first.

All of those would be helpful to see, especially if we can tell what the engine rpms were at the time of the snapshot.

 

[PBandJs_PPV]

All of those would be helpful to see, especially if we can tell what the engine rpms were at the time of the snapshot.

File is too large. May I email it to you?

 

[Fless]

File is too large. May I email it to you?

See if you can attach it to a PM (Start a Conversation)