AutoCodes – Acura – P0303 Acura

P0303 Acura Code - No. 3 Cylinder Misfire Detected

Quick Answer

The crankshaft vibrates slightly when each cylinder fires. Common causes include Valve adjustment, Faulty spark plug #3, Faulty ignition coil #3. 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: P0303 Acura indicates No. 3 Cylinder Misfire Detected.
Common causes: Common causes include Valve adjustment, Faulty spark plug #3, Faulty ignition coil #3.
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.

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Code Popularity 23,961

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 16, 2023

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0303 Acura Description

The crankshaft vibrates slightly when each cylinder fires. If a misfire occurs, the crankshaft rotation speed changes rapidly. The Powertrain Control Module (PCM) monitors the crankshaft rotation speed based on the output pulses from the Crankshaft Position (CKP) Sensor. By monitoring changes in the crankshaft rotation speed, the PCM counts the number of misfires and determines which cylinder is misfiring. If a misfire is detected, a Diagnostic Trouble Code (DTC) is stored.
There are two types of misfire detection: Type 1: When the number of misfires per 200 engine revolutions reaches the level that can damage the three-way catalyst (TWC), a DTC is stored and the MIL blinks. Type 2: When the number of misfires per 1,000 engine revolutions reaches the level that affects exhaust emissions but is not severe enough to immediately damage the catalyst, a DTC is stored, and the MIL comes on.

OBDII Code P0303 Acura - No. 3 Cylinder Misfire Detected - AutoCodes.com — P0303 Acura Code - No. 3 Cylinder Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0303 Acura?

Valve adjustment
Faulty spark plug #3
Faulty ignition coil #3
Clogged or faulty fuel injector #3
Intake air leak
Insufficient cylinder #3 compression
Incorrect fuel pressure

How to Fix the DTC P0303 Acura?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0303 code means that cylinder #3 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 #3. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0303 Acura code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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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 P0303 Acura Code

1. What are the common symptoms of OBDII code P0303 in an Acura?

Symptoms of code P0303 (No. 3 Cylinder Misfire Detected) in an Acura may include rough idling, loss of power, engine vibrations, and an illuminated check engine light.

2. What are the possible causes of a No. 3 cylinder misfire in an Acura?

Common causes of a No. 3 cylinder misfire in an Acura include faulty ignition system components, fuel delivery issues, vacuum leaks, or a malfunctioning fuel injector.

3. How can I diagnose a No. 3 cylinder misfire in my Acura?

Diagnosing a No. 3 cylinder misfire typically involves checking spark plugs, ignition coils, fuel injectors, and conducting a compression test to identify the underlying issue.

4. Can a dirty air filter cause OBDII code P0303 in an Acura?

A dirty air filter is unlikely to directly cause code P0303. However, a severely clogged air filter could affect the air-fuel mixture, leading to misfires in the engine.

5. What are some repair tips for addressing code P0303 in an Acura?

Repair tips for code P0303 include inspecting and replacing faulty spark plugs, ignition coils, fuel injectors, and addressing any vacuum leaks to resolve the misfire issue.

6. Is it safe to continue driving my Acura with OBDII code P0303?

It is not recommended to drive your Acura with code P0303 for an extended period, as persistent misfires can cause damage to the catalytic converter and other engine components.

7. How much does it typically cost to repair OBDII code P0303 in an Acura?

The cost of repairing code P0303 in an Acura can vary depending on the underlying cause of the misfire, but it may range from a few hundred to over a thousand dollars, including parts and labor.

8. Can bad fuel quality trigger OBDII code P0303 in an Acura?

Poor-quality fuel can contribute to misfires, including code P0303. Using high-quality fuel and regular maintenance can help prevent fuel-related misfire issues.

9. Will resetting the check engine light resolve OBDII code P0303 in an Acura?

Resetting the check engine light will not fix the underlying issue causing code P0303. It is crucial to diagnose and address the root cause of the misfire to prevent further damage.

10. How can regular maintenance help prevent OBDII code P0303 in an Acura?

Regular maintenance, such as changing spark plugs, inspecting ignition components, and keeping up with tune-ups, can help prevent misfires and reduce the likelihood of encountering code P0303 in an Acura.