How to change spark plugs

[WRXreX]

Spent 1 1/2 hour in a complete darkness (with small flash light!) and freezing temperature to replace the sparkplugs today. Type of plugs I got are Denso Iridium Power plugs (IK22) that are one step colder than stock plugs.

****warning**** replacing plugs on boxer engine is very different from Honda engine, which takes only 15 min to do. Be prepared to spend at least 45-60 min to replace them if you have never replaced plugs on Subaru vehicle before.

1. Starting from the driver side, remove the washer bottle and the battery to gain good access to the "coil on plug"

2. There is one 12mm bolt you need to "break" and unbolt. Once the bolt is loose, hold it tightly and pull it out. "Coil on plug" will also come out. This "Coil on plug" is also difficult to pull out especially the one near the driver side but it will come out eventually

3. Using 5/8" spark plug socket, unbolt the spark plug and take it out. When you can no longer turn the extension by hand, use a precision torque wrench and torque the plug to 18 ft-lbs.

4. Follow steps 2-3 on the passenger side but be sure to remove the intake box in order to gain access to "coil on plugs"


HOPE THIS HELPS!

[KanosWRX]

How did the car feel after changing the plugs?

[WRXreX]

Believe it or not, my car has been having problem last few months. Car didn't pull hard even in 1-2nd gear @ 14psi. Could be due to oxidized plug similar to the problem either C&D or R&T magazine had on their test WRX car. Now after replacing them with the colder spark plugs, my car feels strong again. I won't make a statement like this if the difference is small, but the difference I feel is quite noticeble. Yes, it is not because of ECU reset.

Tim

[MisterX]

I've changed my plugs, too. My hands were sore and bruised for the best part of a week.

X

[NJwrbT-WRX]

I am interested in the results as well. I have always wondered why they are included in VS0 but not really used in any other stages or talked about that much as a good mod to do.

-joe

[MisterX]

Should anyone report "feeling" results of having changed spark plugs, be skeptical. Unless, of course, the results are posted of a datalog which plots detonation or some similar phenomenom before and after the plugs. Otherwise, there is no noticeable difference.

X

Edit: There are threads here about why some tuners use colder plugs (Vishnu) and others (TurboXS) do not.

[NJwrbT-WRX]

Any non performance benefit upgrading to better plugs or going a step or two colder?

-joe

[MisterX]

You might avoid some detonation. That's a pretty big might, too.

X

[scoobysonj]

Hi, I need to change my plugs in my 2002 wrx, when i disconnect the battery what will happen reference to the ecu, my wrx has had a few mods and maybe remapped, will this be affected when the battery is off? cheers.

[oguitar]

Thanks for searching.

Your tune is stored in memory and should not be erased simply by disconnecting the battery. Good luck.