What does code P0300 mean on a Cadillac and is it safe to drive?
P0300: Random/Multiple Cylinder Misfire Detected. Here's what it means on your Cadillac, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
The PCM has detected misfires across multiple cylinders. This can cause damage to the catalytic converter if driven for long.
Common causes for your Cadillac
- Worn spark plugs or ignition coils
- Clogged or bad fuel injectors
- Low compression
- Vacuum leak, bad MAF, or fuel delivery issue
Symptoms
- Check Engine Light (often flashing under load)
- Rough idle, shaking, loss of power
- Possible smell of unburned fuel
Typical fixes
- Replace spark plugs and coils as needed
- Clean or replace fuel injectors
- Fix vacuum/fuel issues
- Compression test if no obvious cause
Repair cost range
For a Cadillac, repairs for P0300 often fall between $150 and $1200, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Cadillac
Cadillac P0300 on Northstar V8 engines is notorious—carbon buildup, cooling issues, and timing chain wear all contribute. On CTS/SRX with the 3.6L LFX, timing chain tensioner failure is a documented concern at high mileage.
Most commonly affected models
CTS 2008–2015SRX 2010–2016Escalade 2007–2014