Hi guys,

I have a my00 wrx which is also currently experiencing some issues with boosting.

When I go WOT and into full boost the car then starts to backfire through the exhaust - or what seems to be that derived from all the popping that goes on.

I've since replaced the AFM with 2 genuine units...and have also gapped my spark plugs down to 0.65 to no avail.

The only code that comes on is code 23 even though iv already replaced my afm and my o2 sensor.

Thanks guys.

 

Crank sensor.

 

Why do you say so?

I might unbolt it and test the resistance of it tomorrow actually.

I thought these were mainly just responsible for starting the car...

 

My mistake the knock sensor and from experience.

The knock sensor is underneath the TMIC, subject to heat from the engine block and the ingress of all the air flow crap that comes in. They are prone to cracking which allows in moisture giving poor contact.

The knock sensor senses the vibrations of the engine and will decrease acceleration until the sensor is replaced. With a faulty sensor, there is a chance that higher emissions are being produced from the engine because the engine may run hot.

 

generally though itll throw an intermittent CEL 22 for the knock sensor when that cracking of the casing happens

OP: is the CEL 23 always present, permament CEL light?