P0303 Code – Which means, Causes, Signs (& How To Repair)

In case you have scanned your engine pc to see what’s inflicting hassle and located the P0303 code, you would possibly surprise what's going on and find out how to repair it. Fortunately, it doesn’t take a number of troubleshooting to unravel this subject.

On this information, we take a look at the meanings of the P0303 hassle code. We additionally present you what would possibly occur when this happens and consider find out how to restore it. 

Code P0303 Definition

P0303 – Cylinder #3 Misfire Detected

What Does the P0303 Code Imply?

P0303 DTC implies that there’s an engine misfire in cylinder 3. The Powertrain Management Module (PCM) detects {that a} misfiring is happening within the third cylinder within the automobile motor, thereby alerting the engine to set this hassle code. It’s a generic code, making use of to all OBD-II outfitted fashions.

Whereas the P0303 hassle code could be thought-about generic, the repairs may rely on the make and mannequin you drive. If there are a number of misfires occurring, you could possibly additionally see the P0300 code along with different associated codes indicating issues with different cylinders as properly. 

P0303 Hassle Code Signs

If one of many engine cylinders is misfiring, you must discover some efficiency points. Moreover, the Verify Engine Gentle will come on when the code is ready, alerting you to the issue. 

Listed below are a number of the high signs you’ll discover with the P0303 DTC.

Causes of the P0303 Code

When the automobile engine is misfiring, it may be brought on by plenty of issues. In some circumstances, the problems may stem from the ignition system, nevertheless it’s additionally attainable that one thing has failed with the gas system.

Listed below are a number of the most typical causes of the P0303 hassle code.

How Critical is the P0303 Code?

Extreme – The P0303 DTC is taken into account one which ought to be taken critically. Driving with an engine misfire can turn out to be harmful, particularly if the automobile begins to stall in the course of the highway. If the engine stalls, it could be tough to get it began again up, leaving you in a hazardous scenario.

It’s necessary to have the P0303 hassle code examined as quickly as attainable. Working the engine with a misfire can even trigger different engine troubles that may add to the restore invoice. Plus, if the automobile breaks down, you might need to pay for a tow truck. 

What Repairs Can Repair the P0303 Code?

It's essential to carry out an entire prognosis earlier than you try any repairs. In any other case, you could possibly spend pointless cash on elements that aren’t wanted.

Primarily based on what fails most frequently, listed below are just a few of the fixes that could be so as.

• Change spark plug
• Change ignition coil/wires
• Set up a brand new gas injector
• Repair leaking valve
• Repair vacuum leak
• Change piston ring
• Restore leaking head gasket
• Change pc module

Widespread P0303 Analysis Errors

Mostly, the spark plugs, ignition coils, wires or coil pack goes to be in charge for the misfire. Nonetheless, you must by no means assume that’s the issue with out first performing the diagnostic steps we define. You wish to carry out a visible test of the plugs, wires, coils, and coil pack earlier than changing it. 

If these elements look okay, you could transfer on to different elements that could possibly be inflicting the difficulty, such because the gas injectors or valves. You additionally wish to carry out a compression take a look at. Moreover, if there are another hassle codes current, these would possibly assist you slender down what’s occurring. 

How you can Diagnose the P0303 Hassle Code

As knowledgeable mechanic, you wish to comply with a laid-out plan when diagnosing the P0303 code. Gathering the code from the scanner is simply step one of determining what’s incorrect. With the appropriate steps, you'll have a definitive reply to the issue.

Listed below are the commonest diagnostic steps for the P0303 DTC.

1. Acquire the difficulty codes together with your OBD-II scanner and use freeze body information to see what’s occurring. Proceed the troubleshooting based mostly on the opposite hassle codes chances are you'll discover.
2. Reset the codes.
3. Take a look at drive the automobile to see which codes come again.
4. Examine the spark plug, ignition coil, wire or coil pack on cylinder 3 to see whether it is broken or worn. Change if mandatory. You'll be able to attempt to transfer over the spark plug and ignition coil to a different cylinder to see when you get a hassle code on the opposite cylinder as a substitute – in that case substitute the defective spark plugs and ignition coil.
5. Verify the consumption system for a vacuum leak.
6. If this isn’t the issue or the code doesn’t go away, you have to to examine the gas injectors. 
7. In case you have an older automobile, you may also want to have a look at the distributor cap and the ignition cables. 
8. Past this, a compression take a look at of cylinder 3 will likely be wanted. 
9. Verify the camshaft timing and examine the timing belt or shaft if mandatory.
10. If nothing else will be discovered with the diagnostics, you would possibly discover the PCM is unhealthy and must be changed. Nonetheless, with this downside, you’ll possible see different false codes or issues. 

Estimated Price of Restore

Relying on what’s inflicting the issue, you're looking at a various quantity of restore prices. Some points are going to value far lower than others to repair. Beneath we record just a few of the commonest repairs and the common value for elements and labor.

• Change spark plug – $40-$350
• Change ignition coils/wires – $75-$400
• Set up a brand new gas injector – $200-$500
• Repair leaking valve – $500-$2,500
• Change piston ring – $1,000-$5,000
• Restore leaking head gasket – $1,500-$3,000
• Change pc module – $750-$3,500

Mechanics Ideas in regards to the P0303 Code

If you happen to discover that the cylinder 3 spark plug is inflicting the p0303 code, you could possibly merely substitute that plug and transfer on. Nonetheless, it’s at all times a greater thought to switch the entire plugs on the identical time. If one is failing, the others are in all probability shortly behind. Plus, by changing the spark plugs abruptly, you'll be able to keep on a beneficial upkeep schedule with ease. 

You additionally wish to guarantee that the spark plugs are adequately gapped. A niche that's too small or too large can simply result in a misfire. Use a spark plug hole device to make sure the house matches the producer’s specs.

Associated Hassle Codes

Often Requested Questions