Hey fellas,

I've got a '99 S70 non-turbo, and a persisting issue that just threw me two codes yesterday. I just recently had my original transmission die at 220K, and had it replaced with a used one. I've been driving the car for a week since getting it back, but one issue persists and actually got worse yesterday. Car accelerates normally, but something wonky happens when decelerating to a stop. Below about 10mph when braking, the car will get a shudder as the RPM dips from ~1000 to ~600 and flutters. When it threw me the codes while driving, it was acting just as usual, then tranny light started blinking accompanied by the check engine light.

Codes are: P0740 - Torque Converter Clutch circuit/open, P1057 - manufacturer specific

Any idea what might be wrong? Currently thinking some sort of sensor, since it's not a part of the whole transmission block. Also curious if this issue is what destroyed my last tranny. Any help would be appreciated. When I cleared the codes after reading them, they did not come back after driving home last night, even as the shuddering while stopping intensified. Thanks in advance.