2 different issues here. I have a 2001 rx300 with 176k.
Issue 1: Recently I had my exhaust completely replaced. After it was replaced, I noticed it was hesitating to accelerate. Doesn't do it all the time but noticeable. Did not happen prior to exhaust replacement.
Issue 2: At the same time I have noticed it was hard to break. Breaks got really hard to stop. Sometimes at a full stop and car in gear after about 10 secs or so the break pedal wold push a little further down. As if some pressure was released. I checked fluid and thats good. No leak from calipers. Pumped breaks when car was off until it got hard. Turned car on and got travel of the break pedal, so I assume my booster and MC are still functioning. Any help would be appreciated.