Funny problem serious problem
 

2007 s80 v8 awd - just trying to get a idea of whats wrong before i go to the delearship, im handy - did plugs, brakes and rotors, intake manifold pressure sensor, and some other light work

-Hard acceleration from 60 to 80 2-3 times(with few minutes of break intervals) triggers a check engine light and onboard message "shift up or slow down rpms"

-happens at high rpms only

-cylinder 1 misfire
-cylinder 2 misfire
-cylinder 3 misfire
-cylinder 5 misfire
-cylinder 6 misfire
-cylinder 7 misfire
-cylinder 8 misfire

-multiple cylinder misfires

-read online here and there that this could be a catalytic converter going bad?

-plugs were changed at 64000 miles, car has 86000 miles on it

other minor issues:
-buzz noise at cold start up comming from passsenger side muffler, goes away after 30mins
-center inner dash rattle
-driver side heat vent near door panel (middle portion) makes a whine noise after long operation, pushing the brake pedal makes it go away sometimes or turning off the heater
-gear change into reverse feels harsh/thud

thanks to anyone chimes in!

High RPM's and misfires...

Think about what the engine/engine management/spark/voltage/timing have to do with that...

Interesting.

Ignition issues tend to show up under peak cylinder pressure. If it was my car, I would grab a set of cheap copper spark plugs, gap them, install them and go from there. Granted there might not be a lot of miles on the plugs in there, but for the price you might as well isolate them. I guess it could be the cat, but miles are a little low for that.

For the transmission thud, might be time to consider a drain and full with fresh fluid if that hasnt been done. It could also be motor/transmission mounts as well as tired CV joints.

1st problem with the dstc, brake, check engine light, + one other light including a dash message of brake failure: caused my awd system to shut down, I guess there is some pump in the rear of the car that had a temp sensor on it which failed and caused the awd system to turn off.

2nd problem - they took a fuel sample - which turned out okay, and said they want to clear all the codes and have me monitor it, also noted engine is running fine.

Other than that everything checked out okay, with exception to scalding on my rear tires. Thanks guys.