I have a misfire on my 2015 Audi s4 can’t figure out what it is, I’ve replaced spark plugs, moved coil packs around and it doesn’t move cyclinders, thought maybe my cats were clogged causing back pressure since they are right behind the exhaust manifold so I replaced them with straight pipes, still misfiring, the supercharger has intercoolers in it which can leak coolant into the cylinders when they fail, but there’s no sign of a leak, the only other thing I can thing of is a bad injector but I don’t want to just replace them without knowing that’s the issue for sure, it also makes a terrible rattling sound from the exhaust when I go up in rpm’s which only started after the misfire occurred but idk if it’s related or just coincidence, any help?
That’s the thing I took them out completely and put strait pipes in cause I thought the same thing
Noises can telegraph all over a car. Look for anything loose like heat shields either around the exhaust or in the engine compartment that can rattle. Also check that your exhaust pipes are not so close to the car chassis that they might clatter when the engine moves slightly as it revs up.
As far as the misfire, if you suspect an injector swap the injector for cylinder #3 with another and see if the misfire travels with the fuel injector.
makes a terrible rattling sound from the exhaust when I go up in rpm
that would make me suspect the cats
That’s the thing I took them out completely and put strait pipes in cause I thought the same thing
Scotty advises
