Are the Nippon Denso Iridium IK-24 same as the standard PFR-6B NGK
cause after replacing the OE with them the car started to judder when staying to steady revs all over the rpm band?

Elias

 

If they were a direct change over one may be shorting or not firing properly. The iridium plugs just last longer.

 

I've had issues with Denso plugs.
Suggest you change back to NGK.

 

Rt,

Can you be more specific about that?

 

I use the Denso spark pluges with no problem about 2 years.
Where did you buy and install them ?

 

Specific:
WOT gears 3 and 4, poof! One sparkplug blew. Lit my KnockLink all the way. Had to drive on 3cyl to my mech (not far) hoping for the best.

MY01 JDM STI RA, fully std engine and exhaust. Denso IK22 (supposedly equal to NGK Heat #7... apparently not!).

[Edited by RT - 6/9/2002 2:30:55 PM]