my car have jerking rpm (lagging rpm) NO ODB Error. i tired many ways but no luck. someone said it could be from knock sensor. is it safe to unplug the knock sensor for a while to check my problem

our octane fuel is very bad. (but i will not rise rpm above 4000)

is it safe to unplug it? or it could damage to motor also if we driving in low rev?

  • What are you expecting to happen after you have disconnected the sensor?
    – HandyHowie
    Commented Oct 13, 2018 at 12:09
  • Welcome to Motor Vehicle Maintenance & Repair! Commented Oct 13, 2018 at 14:35

1 Answer 1


tl dr: Not a good idea.

Two things:

You can check to see if the knock sensor is going crazy through the ECU, so why disconnect the knock sensor to see? Disconnecting it will not give you any direct data. If there is a real knock problem, you could end up damaging the engine.

Second, if there is an issue with the knock sensor itself, you'd most likely get a trouble code of P0325, which is about a circuit malfunction.

our octane fuel is very bad. (but i will not rise rpm above 4000)

The top rpm doesn't matter much, as it's not about how fast you rev your engine, but rather how hard you run your engine. Knock can occur for several reasons, but it's when you hear it while the engine is being ran hard at lower rpms (below 4k) is when you do damage. Damage produced by knock can occur quickly and is irreversible (without rebuild). Serious knock can cause serious problems. Taking away the protection the computer has built into it can only lead to further issues.

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