2001 Mazda 626 Tight driving

I'll try to explain this, early morning seems to run just fine, I drive peroidocally all day off and on. By mid afternoon, car rpm's seem to be higher and take longer to shift into driving gear. Also brake becomes really tight. When I turn on the AC really seems to run high on the RPM's. I recently had a brake job and the fuel injectors flushed. Before the flush when sitting at a light the hood would shake, but know idles fine, but the driving exceleration seems to be sluggish/tight. Any suggestions??