Please troubleshoot this full-wave rectifier circuit using op-amps
Working with the limitations of output swing , it is possible to barely fit 10Vpp rectified to 5 to 10V with > 10k load on the output stage.  The diode cause the 5Vp positive swing to be inverted towards -0.7 which clips the signal in the 1st stage.  The 2nd stage inverts again with a gain of 2 but the BJT output with a high side Darlington and current source that drops from V+ by 2 to 3 V based on load from 10k to 2K.

The low side Vol is pretty close to 0V with a single Vce(sat) driver.

The solution is to cut positive swing gain then boost it for 2nd stage. This is easily done by reducing R11,R12 by the same % such as 50%. Then unity gain is restored.  R11 cuts stage 1 gain then R12 restores the gain in stage 2 only for positive input swing.

Bonus

If you wanted to eliminate the 5V offset a resistor from 12V to U3-2 of 2.4k will reduce to x mV offset, resulting in 0 to 5V output.  Other ways can achieve the same result.

Since the open loop gain is 1.5e4 the diode voltage error is reduced by 1.5e4, which is the “large signal gain”.