Engine-CodesCadillac – P0301 Cadillac

P0301 Cadillac Code - Cylinder 1 Misfire Detected

Quick Answer

When a Cadillac shows the diagnostic code P0301, it indicates that a misfire has been detected in cylinder 1 of the engine. Common causes include Faulty ignition coil, Worn spark plugs, Clogged fuel injector. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0301 Cadillac indicates Cylinder 1 Misfire Detected.
Common causes
Common causes include Faulty ignition coil, Worn spark plugs, Clogged fuel injector.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Aug 30, 2024
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Code P0301 Cadillac Description

When a Cadillac shows the diagnostic code P0301, it indicates that a misfire has been detected in cylinder 1 of the engine. This means that the fuel-air mixture in that particular cylinder is not igniting properly, leading to a loss of power and efficiency in the vehicle. A misfire can cause a rough idle, hesitation during acceleration, reduced fuel economy, and potentially even engine damage if left unresolved.

OBDII Code P0301 Cadillac - Cylinder 1 Misfire Detected
P0301 Cadillac Code - Cylinder 1 Misfire Detected

Common Causes of P0301 Cadillac

  1. Faulty ignition coil
  2. Worn spark plugs
  3. Clogged fuel injector
  4. Vacuum leak
  5. Low compression in cylinder 1

Symptoms of P0301 Cadillac

  1. Rough idle
  2. Loss of power
  3. Engine vibration
  4. Decreased fuel efficiency
  5. Engine stalling

How to Fix P0301 Cadillac

  1. Start by checking the ignition coil for proper function and replace if necessary.
  2. Inspect and replace the spark plugs in cylinder 1.
  3. Clean or replace the fuel injector for cylinder 1.
  4. Check for any vacuum leaks in the intake system and repair as needed.
  5. Perform a compression test on cylinder 1 to check for any internal engine issues.

Cost to Fix P0301 Cadillac

The typical repair costs for resolving a cylinder 1 misfire in a Cadillac can range from $100 to $500, depending on the specific cause of the issue and the price of parts and labor in your area. Keep in mind that diagnostic time and labor rates at auto repair shops can vary, so it's a good idea to get a few quotes before proceeding with the repair.

Tech Notes for P0301 Cadillac

The P0301 code means that cylinder 1 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 1. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

There is a Factory Service Bulletins for All 2000-2020 Cadillac Models:
2000-2020 Cadillac Factory Service Bulletin OBDII Code P0301
This Factory Service Bulletin explains how this condition may be caused by significant carbon build-up on the intake and/or exhaust valves due to fuel contamination or incomplete burning of the fuel.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0301 Cadillac Code

No Frequently Asked Questions about P0301 Cadillac Code found.

Discuss the causes and fixes for P0301 Cadillac OBDII Code

  • My Cadillac CTS 2005 is misfiring. Changed spark plugs and coils. I'm still getting code p0301.

  • Is there excessive smoke, is the engine running rough? Have you overheated the engine lately?

  • I'm a few years late to the thread but I have the same problems on my 08 cts. No overheating but it has a ruff idle. & it started to squeak

  • Have you replaced any parts yet? The ignition coil and/or spark plugs are the most common problem for the P0301 code, but if you have already replaced those parts, then you may have a problem with the fuel injector.

  • Yeah, those were the first things I replaced. I bought a fuel injector too but didn't change it because I didn't want to keep throwing money into the car without knowing the cause first. So I had a mechanic see it and he said I had no compression in cylinder one. Based on that information he suggested a new engine. I don't know if that's a good fix so I'll look for a second opinion. Anyways, thanks for the help.

  • Had the same issue with P0305 and Mechanic told me new engine needed $4000. Two years later that issue was restored now I am dealing with p0301. Changed coil pack, sparkplugs, fuel injectors, fuel filter. What left I will have to do vacuum leak, fuel pressure before I go too far.

  • What model and year is your vehicle? your next step is to perform a cylinder compression test

  • Cadillac cts 05, v6. 3.5. It got 252000 still drives strong. She loves speed. If I delete the code it won't come up again as long as I didn't stop. If I delete the code and leave it on idle she doesn't like that and check engine would be flashing. I have raise rpm over 800 before it goes away. It idles between 500 and 600rpm rough and over 800 rpm smooth .

  • I was looking for answers on this P0301 code and started researching DIY info. I ran across a video on how to change plugs and coil packs on a 3.6L V6 Cadillac STS VVT motor (2007). Almost as an after thought the guy on the video mentioned how years ago he found out that having a low oil condition doesn't get enough oil to the timing chains and that it gave him this code. I thought why wouldn't you get a low oil or check oil level indication first before any trouble like this ? There is no good excuse for why I hadn't checked my oil in a while so I won't make one up but I added oil, ran this thing and it stopped acting just how it had with the P0301 code. All the misfiring, jerking, bad acceleration and fear my timing chain had gone bad was gone. Keeping my fingers crossed that my issue is resolved with simply adding oil while I keep an eye on it for a few days.

  • Thank you for sharing and I hope that fixes the problem.