Code P0301

I got the light on the dashboard while waiting in line to exit a large parking lot. THe engine had been idling for about 5-7 minutes. Code P0301 is a miss in cylinder 1, however I never felt anything and the engine runs ok to me. The light has been on the dashboard for about 3 weeks now. How should I proceed. I thought it resets itself after 40 starts.

Reply to
Firebird
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It will not clear until the problem is fixed or goes away and then a certain number of good drive cycles. Why not go to Harbor Freight for this?

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JoBo

Reply to
Jo Bo

In article , Firebird wrote: #I got the light on the dashboard while waiting in line to exit a large #parking lot. THe engine had been idling for about 5-7 minutes. Code P0301 #is a miss in cylinder 1, however I never felt anything and the engine runs #ok to me. #The light has been on the dashboard for about 3 weeks now. #How should I proceed. I thought it resets itself after 40 starts.

The code will reset after 40 starts with no problems. The light resets sooner than that. If you light is still on, it's time to check your plug and anything attached to it...

What engine do you have?

/herb

Reply to
Herb Leong

That's the right price for that. Does it handle OBD-III?

Reply to
Scott in Baltimore

It isn't going to reset as long as something is wrong.

I would be checking out cylinder 1 myself.....

You don't say what you are driving, but you likely have a spark plug at least in there and maybe a plug wire with a distributor cap and rotor....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >
Reply to
Mike Romain

You can reset the computer by simply disconnecting the battery for a few seconds or my use of a reader. The readers are available for use at many auto-parts stores... some free of charge or with a small deposit.

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Code - Cylinder #1 MisfireTechnical DescriptionCylinder #1 Misfire Detected What does that mean? A P0301 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #1.

Symptoms Symptoms may include: a.. the engine may be harder to start b.. the engine may stumble / stumble, and/or hesitate c.. other symptoms may also be present Causes A code P0301 may mean that one or more of the following has happened:

a.. Faulty spark plug or wire b.. Faulty coil (pack) c.. Faulty oxygen sensor(s) d.. Faulty fuel injector e.. Burned exhaust valve f.. Faulty catalytic converter(s) g.. Running out of fuel h.. Poor compression i.. Defective computer Possible Solutions If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Reply to
billy ray

Reply to
L.W.( ßill ) Hughes III

Reset the light and wait to see if it returns. Odds are good that it will, and you need new plug wires or a coil if your motor is the type that has a coil for each plug.

AutoZone Parts Stores have the OBD II Code Reader (scan tool) that they will let you use, or they will use it for you, for free.

Reply to
Jeff Strickland

I have the 6 cylinder. I think its a 4.0 ...it runs fine. It does not feel like its missing.

Reply to
Firebird

Sorry, Its a 2001 Cherokee Laredo 6 cyl.

Reply to
Firebird

I had everything changed about 6 months ago at 60,000 miles.

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P0301 Code - Cylinder #1 Misfire> Technical Description> Cylinder #1 Misfire Detected>

Reply to
Firebird

What all is in the 'everything" that was changes 6 months ago?

That doesn't mean one of those new components cannot be the problem now. As with anything mass produced... occasionally a defective part gets through or one fails early.

I think my first move would be to pull the spark plug from the #1 cylinder and examine it carefully for signs of a misfire.

At this point you could swap it with any of the other spark plugs (preferably #6) to see if the code moves to that cylinder or you can just spend the $2 and buy one new plug.

If that fails you can try spraying a MIST of water around the coil rail. sparkplug boot area while watching and listening for a spark leak. This is best done away from shaded or dark area.

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> P0301 Code - Cylinder #1 Misfire>> Technical Description>> Cylinder #1 Misfire Detected>>

Reply to
billy ray

#> In article , #> Firebird wrote: #> #I got the light on the dashboard while waiting in line to exit a large #> #parking lot. THe engine had been idling for about 5-7 minutes. Code #> P0301 #> #is a miss in cylinder 1, however I never felt anything and the engine #> runs #> #ok to me. #> #The light has been on the dashboard for about 3 weeks now. #> #How should I proceed. I thought it resets itself after 40 starts. #>

#> The code will reset after 40 starts with no problems. The light #> resets sooner than that. If you light is still on, it's time to #> check your plug and anything attached to it... #>

#> What engine do you have? #>

#> /herb

#I have the 6 cylinder. I think its a 4.0 ...it runs fine. It does not feel #like its missing.

It is possible you don't feel anything because it is a in-line 6. A missing spark would probably go unnoticed, at least for a little while until you get problems from fuel in the exhaust. Before I had my YJ's original 4.2 I6 replaced, I pretty much had ziltch compression on my number 6 cylinder and I hardly noticed it unless doing 70+ on a steep (for a freeway) incline--then it felt like I was driving my mom's '81 Honda-civic-putt-putt.

On the 4.0, the sparkplugs fire twice per cycle as 3 ignition coils are shared by the 6 cylinders so you may want to also look at the other sparkplug that's tied to the number 1 cylinder's sparkplug.

If you ever look at the engines that are used to demo the snake-oil additives on late night infomercials with sand and other crud dumped on top of the heads, it's always a I6.

You should still check your plug and anything attached to it.

/herb

Reply to
Herb Leong

In article , billy ray wrote: #If that fails you can try spraying a MIST of water around the coil rail. #sparkplug boot area while watching and listening for a spark leak. This is #best done away from shaded or dark area.

Why away from shade or dark areas?

/herb

Reply to
Herb Leong

The 4 liter I-6 firing order is 1,5,3,6,2,4

Cylinders 1 & 6, 5 & 2, and 3 & 4 always fire together.

Reply to
billy ray

It is easier to see sparks in the dark.

Reply to
billy ray

I have the same problem with my 97 TJ. I've changed the plugs, wires, dist. cap, and rotor. I ran STP complete fuel system cleaner hoping that would help, but the light still keeps coming on after erasing the code. I have no symptoms either, so if you figure it out please post the solution. Good luck

Reply to
jongig

Man, I gotta get me one of those magic in-line 6 engines. Missing spark and you wouldn't even notice?

Reply to
bllsht

In article , bllsht wrote: #Man, I gotta get me one of those magic in-line 6 engines. Missing spark and you #wouldn't even notice?

Whatever floats your boat, if you think I'm wrong, then maybe I am. Have you tried it? Prolly not. Have I? Not on purpose.

All I know is that I had a plug wire disconnect on a 4.7 v8 and it was not all that noticable until some load was put on it (the light and code retrival told me more than anything else). I also had a 4.2 i6 with no effective compression on one cylinder and I did not notice anything unless some load was put on it.

FWIW, the new Hemis idle on only on 4 cylinders.

Shrug,

/herb

Reply to
Herb Leong

Reply to
L.W.( ßill ) Hughes III

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