russ29

Can any tell me if it really takes 1.5 hours to replace the plugs in a 99 GS?

Can you also tell me if you go with OEM or other (NGK, Bosch)?

Can anyone send me DIY instructions for replacing said plugs?

Thx!

Navaz

I don't know How long It takes to change the spark plugs, I have not done it myself
I think the only plugs you can use on a gs 400 is the OEM, TM plugs which I use, and I just found out that champion makes a set too.

RAristo

The installation time depends on whether you have a GS3 or GS4. in GS4, it's very easy to change the plugs. There are 4 on each side of the engine and add just a touch of oil lubicant when you insert the new plugs. Cheer.

bravo261

iTrader: (1)

yeah, i've read the 300 is a terror to get to

OsideGs4

How come everybody says the denso iridium are the stock plugs on a gs4 .... I just changed my plugs @ 100k and the old ones I took out were ngk iridium (and I am original owner)...... I hope the densos out perform them. By the way stay away from the torque masters ...... I have a few good friends that work across the street from me at saleen. They said they have experimented with them a few times. After about 30k they popped the head off and noticed a lot of the valves were slightly burnt.( not only a mustang but an explorer,focus, even an s7) Is it worth 5 extra horse power to make your engine run like that... not imo. I'd stay with oem ignition if you are naturally aspirated.There are many more mods that alleviate exhaust or add air flow which is also good for the motor.