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

[richee3]

^^ They may not be owned by the same people and their plugs may not be identical and rebranded, but I'd put money on it that they have the same suppliers and are using the same parts. Unless I have an application that requires a higher grade spark plug, I'll just put whatever's cheapest but works back in the car. In this case, Bosch plugs are known to have problems, NGK's are more expensive than Denso, so I'll just keep Denso platinum plugs in the Celica.