Ok, finally have a quiet car. I went through all the steps after plugs were changed ( plugs were wayyyy overdue 207k, my bad). Also replaced the coils, cleaned the EGR, cooler, manifold, throttle body, replaced pcv, and anything else. Fuel treatment, I like Chevron Techron additive, and heet in tank. Made no difference in noise. Tore my hair out and finally brought to a shop with a better scanner. One of my new plugs had a hairline crack in the porcelain so they replaced it. Ran much better so I took home and replaced all the plugs with Denso plugs. I had made the mistake of using Bosch plugs the first time. This is Taboo! Took it and drove a bit and then a new code popped up. Misfire on cylinder 4 now rattle was back too. Metered coils that I took out and they seemed fine. Took out the aftermarket coil and put an original back in. Misfire and rattle gone! It's been said before but here it is again... Don't use Bosch plugs and only replace coils with original equipment. I'm returning the plugs and coils for full refund but it won't cover the income and time lost. Hope this helps someone
I preach that constantly. You want to save a buck but you save on the dime and sacrifice the quality sadly.
