Sorry if this has been asked before, but I haven't seen it thru the search, so here goes. I have a 98 GS4 with 89K+ miles, getting ready for 90K change. I need to change the plugs, but I am not sure if the factory used platinum or Iridium plugs? Any help would be appreciated.

Thanks
Bob

 

OEM is Denso Iridium plugs

 

thanks much

 

maybe you can try the tq master plugs too

 

The stock plugs for a 98 are ngk iridium ....which i believe in 2001 switched to Denso iridium. I would stay away from torque master's judging by my personal experiences with them in other cars .... but that is just my opinion.

 

what problem did you have?

i have tq master, together with a lot of other members here in norcal, and we are all doing fine so far. would love to hear your stories

 

Ive never actualy tried them in my Gs4. I Used them in my Supra with no signifigent HP increase and a peace broke off nearly damaging my valve and piston.Way too hot of a plug to run forced induction.IMO , I think a plug with a smaller, very concentrated spark, is more effective. I'm happy for all those who they work great for, I must have got some faulty ones. But I'm sure the quality control can not be as good as NGK or Denso. Not really worth the 5 extra HP to me. There are many more mods that alleviate exhaust or add air flow which is also good for the motor.