Original Post: 2002 Volvo S80 T6 odd acceleration. We first thought it was the turbo inlet hose being old and mushy, and compressing and causing it the choke the engine. We replaced that. It felt a little better in terms of performance but didn't fix the odd acceleration issue. Then came the basic things that needed to be done anyways. I seafoamed the fuel, oil, and the vacuum lines. Then we did the belts, thermostat, water pump, idler, ect. because that had to be done anyways, still no. After that I got the fuel pump replaced for free under recall, and the Volvo dealership told me I had a misfire. I did an oil change a few hundred miles after that as well. Also changed the air filter. After that we did all the ignition coils because it was a misfire in #1 and a random one through the rest, thinking that was the issue after all. I've noticed a large change in power, but still I have this issue especially going uphill. Next I'm replacing the TCV myself for an IPD one. After every step I take the car does feel better overall, but this one particular issue remains.