About three days ago I noticed my car (2001 Buick Regal) was acting a bit sluggish when accelerating on the highway, the engine would rev up a bunch and the CEL flashed, but otherwise the car still drove fine. A day later I took the car for a drive and noticed very poor acceleration, but it was still drivable, on the way back home it got much worse, it would take a minute or two to get up to 60mph and it was sputtering a lot. Today I took it for a drive around the neighborhood to see how bad it was - it's to the point where it barely accelerates at all, I can barely make it up any hills, and I noticed this clanking sound even at low speeds.
I disconnected the MAF sensor and took it for a short ride, that seemed to improve it a little bit but not much. After that, I reconnected the MAF then disconnected the TPS sensor and that just made it worse.
The check engine light is not illuminated, I tried pulling codes using an OBD reader but there were no codes to pull.
Does anyone have any suggestions on what to try next?