Knock sensor is reading but values don't match engine behaviour.
P0326 — also written PO326, P 0326, 0326 — is the OBD-II code for knock sensor 1 circuit range/performance. Same code, same fix: this page covers every spelling of it.
This code means the ECU is getting 'fuzzy' feedback from the knock sensor—it's like trying to listen to the radio with too much static. It's a classic headache on Hyundai/Kia units and older Vauxhall Ecotecs.
P0326 is a sensors fault code, typically costing £90–£350 to put right in a UK garage.
What P0326 actually feels like to drive
- Engine feels 'flat' or sluggish, especially when pulling away from roundabouts.
- A faint metallic 'pinking' or rattling sound under heavy load (going uphill).
- Stop-Start system stops working (standard safety lockout for this code).
- Fuel economy drops by 10-15% as the ECU pulls back the timing.
- Intermittent EML that clears itself after a few restarts but keeps coming back.
What causes P0326?
- Loose sensor bolt (very common)
- Failed sensor
- Wiring routing near injector loom
UK vehicles that throw P0326 most often
- Hyundai i30 1.4/1.6 GDi (2012-2017) - Very common software/sensor issue.
- Kia Sportage 1.7 CRDi (2010-2015) - Often wiring related near the starter.
- Vauxhall Astra J 1.4 Turbo (A14NET) - Usually mounting bolt torque issues.
- Ford Focus 1.0 EcoBoost (2012-2018) - Extremely sensitive to sensor positioning.
- Honda Civic 1.8 i-VTEC (2006-2012) - Rodent damage to the sub-harness is common.
How P0326 is fixed
- Torque sensor bolt to spec
- Replace knock sensor
- Reroute wiring
The P0326 misdiagnosis that wastes money
I’ve lost count of how many times I’ve seen brand-new Bosch knock sensors thrown at a car only for the light to pop back on ten miles later. Lads often jump the gun and swap the sensor because it’s a cheap part, but P0326 is usually about the signal quality, not a dead circuit. Nine times out of ten, the sensor bolt has worked itself loose or someone’s been 'in there' and didn't use a torque wrench. If that sensor isn't sitting dead flat against the block at exactly 20Nm, it won't 'hear' the engine right, and the ECU gets suspicious.
What a UK garage should charge for P0326
A proper diagnostic plug-in and live data road test will set you back £50 to £80 at an independent. If it’s just a loose bolt, we’d usually charge an hour’s labour (£60-£90). If the sensor is actually knackered, a quality Delphi or Denso part is about £40-£70. Total job usually lands between £120 and £220. If you go to a main dealer, expect a 'diagnostic fee' of £150 before they even open the bonnet, and a total bill north of £350 once they add their markup.
P0326 repair cost in the UK
Most P0326 repairs land between £90–£350 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0326
If your garage tells you it's a 'faulty sensor' without even putting a torque wrench on it, find another garage. Insist they check the mounting surface for corrosion—especially on older Vauxhalls. If there’s a bit of crusty rust between the sensor and the block, the vibration signal gets muffled and triggers P0326. Also, ask them to check the loom routing. I’ve seen plenty of these where the knock sensor wire is zip-tied too close to the alternator or injector loom, picking up electrical 'noise' that confuses the ECU. A simple reroute costs pennies but fixes the fault for good.
Can you drive with P0326?
Yes but performance may be pulled.
Urgency: medium.