My 2010 Corolla has just over 200K miles, started setting a P0302 a few months ago. Since the miles are so high, just figured good time to replace all coils & plugs. Reset codes, ran fine for a day. At a traffic light the engine fluttered and set the same code again. I had a F-150 with the same code some time ago and after much aggravation, found the MAF sensor defective. So, I replaced the MAF on my Corolla..... no good, still getting P0302. Seems to happen at low idle or on warm start.... I've heard of problems with intake gasket, just not sure i want to just keep spending time & money, without some guidance. Anyone else have this issue???
I’m currently having the same issue. At idle she flutters but not durning take off or driving. Still says a misfire on cylinder 1 but have replaced the plug and coil. Ran a compression test and results showed 90 on 1&2. So I’m currently figuring mine out. Have you tried to seafoam the engine? Could be carbon build in the throttle body/Idle air control valve. Hope this helps