A friend of mine has an 03 plate Impreza WRX PPP. Its been running fine up until now when it developed a slight misfire on wide open throttle, dropped the boost to 10psi and lit the management light up on the dash. Changed the plugs today, replaced them with exactly the same NGK R Platinum's that came out of it, it still has this slight misfire but only on wide open throttle

It has dropped the boost to 10psi in the past but only when 95 fuel has been used, due to knock detection probably, possibly mapped for 97 fuel?

The cars done 33k miles and i'm not sure if the fuel filter has been changed yet, can't see this causing any big problems though?

I've read a few things on here about the Neutral Position Sensor, could this be a possibly problem on this car? Its not a bugeye, shape after.

Just looking for a possible quick fix before it ends up getting plugged into the diagnostics to read the fault codes.

thanks

 

up...

 

Worth taking the crank sensor out and cleaning it. Mine developed a similiar fault, and that cured it

 

ok, will try that before diag

 

it won't be the crank sensor just pop to a dealer and get it diagnosed properly

 

missing under load is classic coil pack failure symptoms.

 

Mine had this, lighting up the CEL with a Cyl1 misfire code. The dealer has swapped the coil packs from cyl1 to cyl3 & vice versa to see if it is the coil pack or a different problem.

 

I got the Neutral Position Sensor replaced on mine and that fixed the problem