Engine code
P0328: Knock sensor signal too high (bank 1)
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $0 | $0 |
| Labor: 0.5 to 1.5 hours × $125 to $175 an hour | $63 | $263 |
| Fees: shop supplies, disposal, diagnostics | $0 | $25 |
| Total, rounded | $60 | $290 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
This is the range for the most common fix, diagnostic scan (check engine light). Which repair your car needs depends on a proper diagnosis.
The knock sensor is sending a signal stronger than normal on cylinder 1's bank. It may be hearing real engine knock, or a loose sensor, a wire touching metal or a failed sensor may be producing noise. The computer pulls back spark timing to protect the engine, which costs power.
- Safe to drive?
- Short trips only
- Most common cause
- Failed knock sensor
Drive gently. If you hear real pinging, avoid hard acceleration.
What you may notice
- Reduced power
- Hesitation
- Check-engine light
Common causes, most likely first
- Failed knock sensor
- Wiring touching metal
- Loose sensor bolt
- Real engine knock
Check this first
Make sure you are using the fuel grade the owner manual calls for, since low octane can cause real knock. Then check the sensor connector and look for wires touching a hot or moving part.
Other repairs that sometimes fix P0328
| Repair | Typical range, Boston |
|---|---|
| CAN bus wiring repair | $190 to $1,275 |
| ECU / engine control module replacement | $430 to $2,350 |
Before you pay
- Ask the shop what test showed this part is the cause, not just that the code appeared.
- Ask for parts and labor listed separately, and for the hours.
- Ask for a written OK before any extra work. Massachusetts rules require written authorization before repairs.
Got a quote already? Check it against the range. Want to see if your car has a recall tied to this problem? Check recalls by VIN.
Need to read a code yourself? OBD-II scanners on eBay (affiliate link, disclosure).
P0328 questions
Is it real knock?
It is possible, which is why the engine should be listened to first. A real knock or deep ticking noise means the problem is inside the engine, not the sensor, so get it checked soon.
Does octane matter?
Yes. Using a lower octane than the manual requires can cause knock, especially on turbo or high-compression engines. Filling up with the recommended grade is a low-cost step that can help.
Is it a costly repair?
It depends on whether the sensor is under the intake manifold. The part is cheap, but when it sits under other parts, labor is much of the price, so ask for the labor hours.
How much does it cost to fix P0328?
The most common fix, diagnostic scan (check engine light), has a typical range of $60 to $290 in Boston. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
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Code meaning written in our own words. Some codes mean different things on different makes, so check your scan tool or manual. Not a repair shop, estimates only.