diff --git a/xos/synchronizers/new_base/event_loop.py b/xos/synchronizers/new_base/event_loop.py
index 924a45b..9a87b56 100644
--- a/xos/synchronizers/new_base/event_loop.py
+++ b/xos/synchronizers/new_base/event_loop.py
@@ -35,9 +35,11 @@
 
 log = create_logger(Config().get('logging'))
 
+
 class StepNotReady(Exception):
     pass
 
+
 class ExternalDependencyFailed(Exception):
     pass
 
@@ -55,7 +57,6 @@
 DRIVER = NoOpDriver()
 
 
-
 def set_driver(x):
     global DRIVER
     DRIVER = x
@@ -64,7 +65,7 @@
 class XOSObserver:
     sync_steps = []
 
-    def __init__(self, sync_steps, log = log):
+    def __init__(self, sync_steps, log=log):
         # The Condition object via which events are received
         self.log = log
         self.step_lookup = {}
@@ -89,7 +90,7 @@
 
     def load_dependency_graph(self):
         dep_path = Config.get("dependency_graph")
-        self.log.info('Loading model dependency graph', path = dep_path)
+        self.log.info('Loading model dependency graph', path=dep_path)
 
         try:
             dep_graph_str = open(dep_path).read()
@@ -116,14 +117,16 @@
                 True: model_dependency_graph_rev,
                 False: model_dependency_graph
             }
-            self.log.info("Loaded dependencies", edges = model_dependency_graph.edges())
+            self.log.info(
+                "Loaded dependencies",
+                edges=model_dependency_graph.edges())
         except Exception as e:
-            self.log.exception("Error loading dependency graph", e = e)
+            self.log.exception("Error loading dependency graph", e=e)
             raise e
 
     def load_sync_steps(self):
         model_to_step = defaultdict(list)
-        external_dependencies = [] 
+        external_dependencies = []
 
         for s in self.sync_steps:
             if not isinstance(s.observes, list):
@@ -143,7 +146,9 @@
 
         self.model_to_step = model_to_step
         self.external_dependencies = list(set(external_dependencies))
-        self.log.info('Loaded external dependencies', external_dependencies = external_dependencies)
+        self.log.info(
+            'Loaded external dependencies',
+            external_dependencies=external_dependencies)
         self.log.info('Loaded model_map', **model_to_step)
 
     def reset_model_accessor(self, o=None):
@@ -171,7 +176,7 @@
             model_accessor.journal_object(o, "syncstep.call.delete_record")
             log.debug("Deleting object", **o.tologdict())
 
-            step.log = log.bind(step = step)
+            step.log = log.bind(step=step)
             step.delete_record(o)
             step.log = self.log
 
@@ -180,7 +185,6 @@
             model_accessor.journal_object(o, "syncstep.call.delete_set_reap")
             o.backend_need_reap = True
             o.save(update_fields=['backend_need_reap'])
-        
 
     def sync_record(self, o, log):
         try:
@@ -200,7 +204,7 @@
 
         log.debug("Syncing object", **o.tologdict())
 
-        step.log = log.bind(step = step)
+        step.log = log.bind(step=step)
         step.sync_record(o)
         step.log = self.log
 
@@ -216,11 +220,12 @@
         o.backend_code = 1
         model_accessor.journal_object(o, "syncstep.call.save_update")
         o.save(update_fields=['enacted', 'backend_status', 'backend_register'])
-        log.info("Saved sync object, new enacted", enacted = new_enacted)
+        log.info("Saved sync object, new enacted", enacted=new_enacted)
 
     """ This function needs a cleanup. FIXME: Rethink backend_status, backend_register """
+
     def handle_sync_exception(self, o, e):
-        self.log.exception("sync step failed!", e = e, **o.tologdict())
+        self.log.exception("sync step failed!", e=e, **o.tologdict())
         current_code = o.backend_code
 
         if hasattr(e, 'message'):
@@ -228,7 +233,8 @@
         else:
             status = str(e)
 
-        if isinstance(e, InnocuousException) or isinstance(e, DeferredException):
+        if isinstance(e, InnocuousException) or isinstance(
+                e, DeferredException):
             code = 1
         else:
             code = 2
@@ -291,15 +297,19 @@
                 o.backend_status = o.backend_status[:1024]
                 o.save(update_fields=['backend_status',
                                       'backend_register', 'updated'])
-            except BaseException,e:
-                self.log.exception("Could not update backend status field!", e = e)
+            except BaseException as e:
+                self.log.exception(
+                    "Could not update backend status field!", e=e)
                 pass
 
     def sync_cohort(self, cohort, deletion):
-        log = self.log.bind(thread_id = threading.current_thread().ident)
+        log = self.log.bind(thread_id=threading.current_thread().ident)
         try:
             start_time = time.time()
-            log.debug("Starting to work on cohort", cohort = cohort, deletion = deletion)
+            log.debug(
+                "Starting to work on cohort",
+                cohort=cohort,
+                deletion=deletion)
 
             cohort_emptied = False
             dependency_error = None
@@ -323,14 +333,18 @@
                         else:
                             self.sync_record(o, log)
                     except ExternalDependencyFailed:
-                        dependency_error = 'External dependency on object %s id %d not met'%(o.__class__.__name__, o.id)
+                        dependency_error = 'External dependency on object %s id %d not met' % (
+                            o.__class__.__name__, o.id)
                         dependency_error_code = 1
                     except (DeferredException, InnocuousException, Exception) as e:
                         dependency_error, dependency_error_code = self.handle_sync_exception(
                             o, e)
 
                 except StopIteration:
-                    log.debug("Cohort completed", cohort = cohort, deletion = deletion)
+                    log.debug(
+                        "Cohort completed",
+                        cohort=cohort,
+                        deletion=deletion)
                     cohort_emptied = True
         finally:
             self.reset_model_accessor()
@@ -362,7 +376,7 @@
 
         for step_class in step_list:
             step = step_class(driver=self.driver)
-            step.log = self.log.bind(step = step)
+            step.log = self.log.bind(step=step)
 
             if not hasattr(step, 'call'):
                 pending = step.fetch_pending(deletion)
@@ -374,7 +388,10 @@
                 # This needs to be dropped soon.
                 pending_steps.append(step)
 
-	self.log.debug('Fetched pending data', pending_objects = pending_objects, legacy_steps = pending_steps)
+        self.log.debug(
+            'Fetched pending data',
+            pending_objects=pending_objects,
+            legacy_steps=pending_steps)
         return pending_objects, pending_steps
 
     """ Automatically test if a real dependency path exists between two objects. e.g.
@@ -424,7 +441,7 @@
                         raise AttributeError
                 except AttributeError as e:
                     self.log.debug(
-                        'Could not check object dependencies, making conservative choice', src_object = src_object, sa = sa, o1 = o1, o2 = o2)
+                        'Could not check object dependencies, making conservative choice', src_object=src_object, sa=sa, o1=o1, o2=o2)
                     return True
                 src_object = dst_object
 
@@ -468,18 +485,17 @@
         for i in r:
             oG.add_node(i)
 
-        for v0, v1 in mG.edges():
-            try:
-                for i0 in range(n):
-                   for i1 in range(n):
-                       if i0 != i1:
-                            if not deletion and self.concrete_path_exists(
-                                    objects[i0], objects[i1]):
-                                oG.add_edge(i0, i1)
-                            elif deletion and self.concrete_path_exists(objects[i1], objects[i0]):
-                                oG.add_edge(i0, i1)
-            except KeyError:
-                pass
+        try:
+            for i0 in range(n):
+                for i1 in range(n):
+                    if i0 != i1:
+                        if not deletion and self.concrete_path_exists(
+                                objects[i0], objects[i1]):
+                            oG.add_edge(i0, i1)
+                        elif deletion and self.concrete_path_exists(objects[i1], objects[i0]):
+                            oG.add_edge(i0, i1)
+        except KeyError:
+            pass
 
         components = weakly_connected_component_subgraphs(oG)
         cohort_indexes = [reversed(topological_sort(g)) for g in components]
@@ -499,12 +515,13 @@
             for deletion in (False, True):
                 objects_to_process = []
 
-                objects_to_process, steps_to_process = self.fetch_pending(deletion)
+                objects_to_process, steps_to_process = self.fetch_pending(
+                    deletion)
                 dependent_cohorts = self.compute_dependent_cohorts(
                     objects_to_process, deletion)
 
                 threads = []
-                self.log.debug('In run once inner loop', deletion = deletion)
+                self.log.debug('In run once inner loop', deletion=deletion)
 
                 for cohort in dependent_cohorts:
                     thread = threading.Thread(
@@ -527,9 +544,10 @@
                 # Run legacy synchronizers, which do everything in call()
                 for step in steps_to_process:
                     try:
-                        step.call()
-                    except Exception,e:
-                        self.log.exception("Legacy step failed", step = step, e = e)
+                        step.call(deletion=deletion)
+                    except Exception as e:
+                        self.log.exception(
+                            "Legacy step failed", step=step, e=e)
 
             loop_end = time.time()
 
@@ -542,7 +560,7 @@
         except Exception as e:
             self.log.exception(
                 'Core error. This seems like a misconfiguration or bug. This error will not be relayed to the user!',
-                e = e)
+                e=e)
             self.log.error("Exception in observer run loop")
 
             model_accessor.update_diag(