MY00 UK Impreza - CE light when cold...

[Orangecurry]

Morning all.

My Impreza has just started showing the CEL, about two/three minutes into a journey from cold, and the light is on for approx. one minute, then it goes out.

When the CEL is on, the engine feels slightly hesitant or 'pulsing' - at all other times it is fine.

I'm imagining it is a sensor (the car has done 94k miles, FSH from new), so before I give it to Subaru, what are the likely candidates please?

I've done a JECS ecu 'reset', and no fault codes are showing (CEL pulsing at 1/2 second intervals).

[RobCrezz]

I think it would be worth posting this on a impreza forum too. Sorry I cant help any more.

[Orangecurry]

Thanks Rob - I just thought Vixpy1 and ScoobieWRX might want some fun with this first.

[RobCrezz]

Orangecurry said:

Thanks Rob - I just thought Vixpy1 and ScoobieWRX might want some fun with this first.

My random guess is O2 sensor (lambda)!

[Orangecurry]

update:

Driving the car from 'cold' this afternoon, the CEL came on (two minutes into the journey again) and so I quickly pulled over, ignition off, attached the greens&blacks, ignition on, and got 2 long and 2 short pulses.

So it seems to be the Knock Sensor.

Is it OK to drive with this temporary error (lasts one minute at journey start)?

[Animal]

If it is a faulty knock sensor and the fault is only showing at the start of your journeys, then I'm guessing that you should be fine as long as you drive off-boost?

Best,

Animal

[DaveV6]

Get one from a breakers to try, think it was about £15 when I last got one a couple of years ago. Easy enough to fit apart from having to take off the intercooler.