ym42

Latest update. Replaced the plugs ( which were visibly worn - 20-30% larger gaps and lots of brown sediment ). Tested the car, pulls harder but cant clear 5000RPM in 3rd gear, along with some serious pinging. I am thinking exhaust restriction ( failed cat ). I have 0430 code for a long time and it might be related. Code 0430 is on the same side/bank with misfiring cylinders - 5 and 6...

jpplaw

Your theory makes sense, backed up exhaust will lean cylinders

ym42

Update 2.

Went to a local muffler shop today, I had some work done there before. Guys offered to install an OEM direct-fit H-pipe with converters if I bring it in. Found it online ( Walker brand ) on Advance Auto site cheaper than on RockAuto and other places - not bad, just 342$. Free shipping too ( rock auto wanted 130$ freight LOL). Ordered already, going to get delivered straight to the muffler shop ( its Meinecke but the guys are very decent there ). Cant wait to see the results.

ym42

Update 3. Problem fixed!!! The culprit were the plugged converters, just as I thought ( funny how long it took me to realize this ). Had the new cats installed today, and wow - the car feels amazing! Its like driving a new car - engine revving up easier and faster, pulling relentlessly all the way to 6K, spinning the wheels etc. Feels like I gained 30-40% more power. I have not felt this for a long time. I guess I am going to wait with getting that S5 or a supercharger...;-) The car also sounds much louder somehow, which I like too... Glad to have it fixed!