Today was stationary in traffic and all of a sudden engine was about to cut out and stall. It didn't stall, and I was able to drive home safely at low revs. It sounded weird and not lile a smooth gti engine sound. It stryggled to pull. The car also has a dump valve that hisses, and sounded pretty faint to me as I was driving. The engine now sounds like a moped or motorcycle. Engine shuddering, engine management light flashes and then goes away! Is this an exhaust/cat conv issue or blown or is ita more engine related issue? Have Audi R8 coil packs and NGK spark plugs that are recommended for my car. Car feels like it is loosing breath and wants to stall. Not picking up speak!
Anyone have a clue what this could be as I dong want to drive it and do it any damage?