Runs like crap after spark plug change Options

[Con99vert]

99 Celica GT, Automatic. I wasn't sure how long it had been since the spark plugs had been changed so I decided to pick some up while I was at the store today. I picked up a set of Bosch Platinum +2 (4303) and installed them once I got home. The old plugs didn't look too bad except 2 of them that had some oil on the porcelain from when I spilled some a few weeks earlier. The platinum 2's do not require any gapping so I just pulled the old ones and installed the new plugs in about 10 minutes. Then I changed the air filter and started the car. It was idling kind of rough, and stumbling very low, maybe as low as 300 rpm. I revved it up slowly a couple times and it felt like the throttle response was lagging until the rpms got higher and then it would smooth out. I drove it from one side of my parkinglot to the other, maybe 300 feet, and it was really stumbling and gutless. It stumbled less as it accelerated. Does the Celica not like the Bosch Platinum 2 plugs, or did I maybe get a bad batch? Any help I can get would be appreciated. Thanks

[tjblacrosse]

I can not help myself but laugh at the many people who buy platinum and iridium sparkplugs for a car that has an ignition system set up for OEM plugs. Do your research people, those kinds of sparkplugs have too much resistance from the higher grade metals used, causing them to have a weaker spark (although they say to have a better and stronger spark). If you aren't sure what spark plugs to get, look in the freaking manual it's there for a reason!

[DEATH]

I can not help myself but laugh at the many people who buy platinum and iridium sparkplugs for a car that has an ignition system set up for OEM plugs. Do your research people, those kinds of sparkplugs have too much resistance from the higher grade metals used, causing them to have a weaker spark (although they say to have a better and stronger spark). If you aren't sure what spark plugs to get, look in the freaking manual it's there for a reason!

I can not help but laugh at your statement.
1st off - OEM [Denso] are platinum plugs, I have looked in my manual and that backs it up as well.
2nd - Iridium plugs make a nice longer lasting upgrade. Do they make the car faster? No. But they will outlast the copper plugs by a long time.

BTW guys I have spoken with more than a few representative from both Denso and NGK and they all say the same thing - Denso and NGK are the same company and their spark plugs are identical. The whole point in having two brands is one is an OEM focused company that also sells in the aftermarket and the other is branded a "performance" aftermarket type - that's it.
I would never use Bosch plugs on my Celica - I and others have had too many problems with them - this thread is a good example.