Have a look at ; www.carbasics.co.uk
It is important to know the location of the spark plugs while owning a car. In a 2002 Subaru Impreza WRX there are spark plugs near the bottom of the engine block on each side of the car.
two spark plugs are located to the right side of the engine and the other two spark plugs are located on the left side of the engine.
you have to remove the washer bottle and the battery and the air duct then remove the coil packs then spark plugs easy
try changing the spark plugs you will get loads of highley technical answers on here but its normally the simple solution that works i had the very same problem on my impreza and all it needed was a new set of plugs..
If your Subaru Impreza runs lumpy after installing new spark plugs, it could be due to a few reasons. First, the new plugs may not be properly gapped, leading to inconsistent firing. Additionally, if the ignition coils or wires are worn, they may not be delivering adequate spark to the new plugs. Lastly, there may be an underlying issue such as a vacuum leak or fuel delivery problem that has become more noticeable after the maintenance.
Cam sensor and/or crank sensor.
any size that works usually a 3/8th ratchet You probably meant what size socket Its either 5/8th if the plugs are small or 13/16th if they are big
4 i think
Check the spark plugs themselves. I have a '99 Impreza and one of the plugs cracked and I was getting a terrible performance. The plug actually came apart and that was NOT good. Once we got the old plug out we got a new one in and it ran fine.
you dont
Generally, to replace spark plugs on a Subaru vehicle, the spark plug boot should be removed. Then, the old spark plugs should be removed using a socket wrench, and replaced with new ones.