diff --git a/ironic/common/states.py b/ironic/common/states.py
index 4feec36d75..544fc78339 100644
--- a/ironic/common/states.py
+++ b/ironic/common/states.py
@@ -123,9 +123,7 @@ CLEANING = 'cleaning'
 """ Node is being automatically cleaned to prepare it for provisioning. """
 
 CLEANFAIL = 'clean failed'
-""" Node failed cleaning. This requires operator intervention to
-resolve.
-"""
+""" Node failed cleaning. This requires operator intervention to resolve. """
 
 ERROR = 'error'
 """ An error occurred during node processing.
diff --git a/ironic/conductor/manager.py b/ironic/conductor/manager.py
index c4af0629c6..c1331109cc 100644
--- a/ironic/conductor/manager.py
+++ b/ironic/conductor/manager.py
@@ -797,14 +797,14 @@ class ConductorManager(periodic_task.PeriodicTasks):
         except (exception.InvalidParameterValue,
                 exception.MissingParameterValue) as e:
             node.last_error = (_('Failed to validate power driver interface. '
-                               'Can not clean instance. Error: %(msg)s') %
+                                 'Can not clean instance. Error: %(msg)s') %
                                {'msg': e})
             task.process_event('fail')
             return
 
         # TODO(JoshNang) Implement
         # Move to AVAILABLE
-        LOG.debug('Cleaning complete for node %s' % node.uuid)
+        LOG.debug('Cleaning complete for node %s', node.uuid)
         task.process_event('done')
 
     @messaging.expected_exceptions(exception.NoFreeConductorWorker,
diff --git a/ironic/drivers/base.py b/ironic/drivers/base.py
index 4ef2b4928d..5ad5cc05b0 100644
--- a/ironic/drivers/base.py
+++ b/ironic/drivers/base.py
@@ -150,7 +150,7 @@ class BaseInterface(object):
         return self.clean_steps
 
     def execute_clean_step(self, task, step):
-        """Execute a the clean step on task.node.
+        """Execute the clean step on task.node.
 
         Clean steps should take a single argument: a TaskManager object.
         Steps can be executed synchronously or asynchronously. Steps should
@@ -162,8 +162,9 @@ class BaseInterface(object):
 
         :param task: A TaskManager object
         :param step: A CleanStep object to execute
-        :returns: states.CLEANING if the method is complete, or None if
-            the step will continue to execute asynchronously.
+        :returns: None if this method has completed synchronously, or
+            states.CLEANING if the step will continue to execute
+            asynchronously.
         """
         return getattr(self, step.get('step'))(task)
 
diff --git a/ironic/tests/conductor/test_manager.py b/ironic/tests/conductor/test_manager.py
index 388fdbe817..a459e19104 100644
--- a/ironic/tests/conductor/test_manager.py
+++ b/ironic/tests/conductor/test_manager.py
@@ -1363,6 +1363,7 @@ class DoNodeDeployTearDownTestCase(_ServiceSetUpMixin,
         self._start_service()
         self.service._do_node_tear_down(task)
         node.refresh()
+        # Node will be moved to AVAILABLE after cleaning, not tested here
         self.assertEqual(states.CLEANING, node.provision_state)
         self.assertEqual(states.AVAILABLE, node.target_provision_state)
         self.assertIsNone(node.last_error)
@@ -1382,6 +1383,7 @@ class DoNodeDeployTearDownTestCase(_ServiceSetUpMixin,
         self.service.do_node_tear_down(self.context, node.uuid)
         self.service._worker_pool.waitall()
         node.refresh()
+        # Node will be moved to AVAILABLE after cleaning, not tested here
         self.assertEqual(states.CLEANING, node.provision_state)
         self.assertEqual(states.AVAILABLE, node.target_provision_state)
         self.assertIsNone(node.last_error)
@@ -1461,7 +1463,6 @@ class DoNodeDeployTearDownTestCase(_ServiceSetUpMixin,
 
     @mock.patch('ironic.conductor.manager.ConductorManager._spawn_worker')
     def test_do_provision_action_provide(self, mock_spawn):
-
         # test when a node is cleaned going from manageable to available
         node = obj_utils.create_test_node(
             self.context, driver='fake',
@@ -1471,6 +1472,7 @@ class DoNodeDeployTearDownTestCase(_ServiceSetUpMixin,
         self._start_service()
         self.service.do_provisioning_action(self.context, node.uuid, 'provide')
         node.refresh()
+        # Node will be moved to AVAILABLE after cleaning, not tested here
         self.assertEqual(states.CLEANING, node.provision_state)
         self.assertEqual(states.AVAILABLE, node.target_provision_state)
         self.assertIsNone(node.last_error)