P0300 on NISSAN ALTIMA
What P0300 Means on Your NISSAN ALTIMA
Real NISSAN ALTIMA Owner Reports (Source: NHTSA Complaints Database)
"Carbon build-up on valves causing misfire and the break down of the catalyst. codes p0300 and p0303 stored in ecm. required replacement of long engine assembly and exhaust manifold. initially, dealership cited need to replace ignition coil, software update, fuel line flush."
"My check engine light came on today. took my car to baker nissan dealership for them to put it on diagnostic machine. i was charged $135. no work was done since i am out of warranty and extended warranty. they told me the engine was misfiring. two codes appeared p0304 and p0300."
Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.
Common Causes of P0300 on NISSAN ALTIMA
Percentages based on NHTSA complaint component analysis for this vehicle.
Complaint Trend by Year
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50-$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.