2007 volvo s40 2.4 misfire

[jasonsautomotive]

looking for some input here, not sure where to go next. car had misfire codes and cat damage code. we replaced cat , rear o2 sensor and still have misfire at idle on cyl 5. bought new spark plug and coil and it made no difference....even swapped plug and coil from cyl 2 to cyl 5 and misfire stayed at cyl 5. did compression check and all cylinders were around 160. if you hold the throttle around 1500 rpm's the misfire will clear up and if you drive the car the misfire gets really bad and will cause cyl 3 and cyl 4 to have occasional misfire. we also swapped injectors from cyl 1 to cyl 5 and misfire stayed on 5. the only thing i can imagine is possibly a valve issue or a crankshaft sensor. i read an earlier post about spark plugs fixing a similar issue, but seeing how i moved the plug and coil from cyl 2 which never had a misfire to cyl 5 and misfire is still on 5 and cyl 2 is running smooth i dont think thats the cause. maf seems to be working correctly as well as front o2 sensor. im really frustrated with his. the only other thing ive been told is possibly a crankshaft sensor ( but misfire is usually on cyl 5) or the ground wire for cyl #5 coil. any advice/ideas would be greatly appreciated!
brad

[jimmy57]

Time to check valve clearance and inspect for a broken valve spring.

Broken valve spring will not give low compression test in all cases.

If you have inspection camera you could look for contact mark on piston top.

[FLXC90]

Jimmy57; due to design how is valve clearance checked on these? pull upper half of head and...?

A Friend has an '11 C70T5 75k ish, injector replaced and coils swapped, misfire stays on cyl 4. He's running iridium plugs, I suggested he get Volvo plugs. Misfire only occurs on heavy acceleration. Consistently codes 0304.