diff --git a/tempest/api/compute/images/test_images.py b/tempest/api/compute/images/test_images.py
index ed316ef..5de2436 100644
--- a/tempest/api/compute/images/test_images.py
+++ b/tempest/api/compute/images/test_images.py
@@ -32,22 +32,6 @@
         cls.client = cls.images_client
         cls.servers_client = cls.servers_client
 
-        cls.image_ids = []
-
-    def tearDown(self):
-        """Terminate test instances created after a test is executed."""
-        for image_id in self.image_ids:
-            self.client.delete_image(image_id)
-            self.image_ids.remove(image_id)
-        super(ImagesTestJSON, self).tearDown()
-
-    def __create_image__(self, server_id, name, meta=None):
-        resp, body = self.client.create_image(server_id, name, meta)
-        image_id = data_utils.parse_image_id(resp['location'])
-        self.client.wait_for_image_status(image_id, 'ACTIVE')
-        self.image_ids.append(image_id)
-        return resp, body
-
     @test.attr(type=['negative', 'gate'])
     def test_create_image_from_deleted_server(self):
         # An image should not be created if the server instance is removed
@@ -60,8 +44,8 @@
         name = data_utils.rand_name('image')
         meta = {'image_type': 'test'}
         self.assertRaises(exceptions.NotFound,
-                          self.__create_image__,
-                          server['id'], name, meta)
+                          self.create_image_from_server,
+                          server['id'], name=name, meta=meta)
 
     @test.attr(type=['negative', 'gate'])
     def test_create_image_from_invalid_server(self):
@@ -71,8 +55,9 @@
         meta = {'image_type': 'test'}
         resp = {}
         resp['status'] = None
-        self.assertRaises(exceptions.NotFound, self.__create_image__,
-                          '!@#$%^&*()', name, meta)
+        self.assertRaises(exceptions.NotFound,
+                          self.create_image_from_server,
+                          '!@#$%^&*()', name=name, meta=meta)
 
     @test.attr(type=['negative', 'gate'])
     def test_create_image_from_stopped_server(self):
diff --git a/tempest/api/network/admin/test_l3_agent_scheduler.py b/tempest/api/network/admin/test_l3_agent_scheduler.py
index 7c02787..eb397ba 100644
--- a/tempest/api/network/admin/test_l3_agent_scheduler.py
+++ b/tempest/api/network/admin/test_l3_agent_scheduler.py
@@ -26,6 +26,7 @@
 
         List routers that the given L3 agent is hosting.
         List L3 agents hosting the given router.
+        Add and Remove Router to L3 agent
 
     v2.0 of the Neutron API is assumed. It is also assumed that the following
     options are defined in the [network] section of etc/tempest.conf:
@@ -37,28 +38,49 @@
         if not test.is_extension_enabled('l3_agent_scheduler', 'network'):
             msg = "L3 Agent Scheduler Extension not enabled."
             raise cls.skipException(msg)
+        # Trying to get agent details for L3 Agent
+        resp, body = cls.admin_client.list_agents()
+        agents = body['agents']
+        for agent in agents:
+            if agent['agent_type'] == 'L3 agent':
+                cls.agent = agent
+                break
+        else:
+            msg = "L3 Agent not found"
+            raise cls.skipException(msg)
 
     @test.attr(type='smoke')
     def test_list_routers_on_l3_agent(self):
-        resp, body = self.admin_client.list_agents()
-        agents = body['agents']
-        for a in agents:
-            if a['agent_type'] == 'L3 agent':
-                agent = a
         resp, body = self.admin_client.list_routers_on_l3_agent(
-            agent['id'])
+            self.agent['id'])
         self.assertEqual('200', resp['status'])
 
     @test.attr(type='smoke')
-    def test_list_l3_agents_hosting_router(self):
-        name = data_utils.rand_name('router-')
+    def test_add_list_remove_router_on_l3_agent(self):
+        l3_agent_ids = list()
+        name = data_utils.rand_name('router1-')
         resp, router = self.client.create_router(name)
+        self.addCleanup(self.client.delete_router, router['router']['id'])
+        resp, body = self.admin_client.add_router_to_l3_agent(
+            self.agent['id'], router['router']['id'])
         self.assertEqual('201', resp['status'])
         resp, body = self.admin_client.list_l3_agents_hosting_router(
             router['router']['id'])
         self.assertEqual('200', resp['status'])
-        resp, _ = self.client.delete_router(router['router']['id'])
-        self.assertEqual(204, resp.status)
+        for agent in body['agents']:
+            l3_agent_ids.append(agent['id'])
+            self.assertIn('agent_type', agent)
+            self.assertEqual('L3 agent', agent['agent_type'])
+        self.assertIn(self.agent['id'], l3_agent_ids)
+        del l3_agent_ids[:]
+        resp, body = self.admin_client.remove_router_from_l3_agent(
+            self.agent['id'], router['router']['id'])
+        self.assertEqual('204', resp['status'])
+        resp, body = self.admin_client.list_l3_agents_hosting_router(
+            router['router']['id'])
+        for agent in body['agents']:
+            l3_agent_ids.append(agent['id'])
+        self.assertNotIn(self.agent['id'], l3_agent_ids)
 
 
 class L3AgentSchedulerTestXML(L3AgentSchedulerTestJSON):
diff --git a/tempest/common/rest_client.py b/tempest/common/rest_client.py
index 66b6fe7..36ddb40 100644
--- a/tempest/common/rest_client.py
+++ b/tempest/common/rest_client.py
@@ -409,7 +409,7 @@
         elif ctype.lower() in TXT_ENC:
             parse_resp = False
         else:
-            raise exceptions.RestClientException(str(resp.status))
+            raise exceptions.InvalidContentType(str(resp.status))
 
         if resp.status == 401 or resp.status == 403:
             raise exceptions.Unauthorized()
@@ -451,25 +451,26 @@
                     # exception.
                     raise exceptions.InvalidHTTPResponseBody(message)
                 else:
-                    # I'm seeing both computeFault
-                    # and cloudServersFault come back.
-                    # Will file a bug to fix, but leave as is for now.
-                    if 'cloudServersFault' in resp_body:
-                        message = resp_body['cloudServersFault']['message']
-                    elif 'computeFault' in resp_body:
-                        message = resp_body['computeFault']['message']
-                    elif 'error' in resp_body:  # Keystone errors
-                        message = resp_body['error']['message']
-                        raise exceptions.IdentityError(message)
-                    elif 'message' in resp_body:
-                        message = resp_body['message']
+                    if isinstance(resp_body, dict):
+                        # I'm seeing both computeFault
+                        # and cloudServersFault come back.
+                        # Will file a bug to fix, but leave as is for now.
+                        if 'cloudServersFault' in resp_body:
+                            message = resp_body['cloudServersFault']['message']
+                        elif 'computeFault' in resp_body:
+                            message = resp_body['computeFault']['message']
+                        elif 'error' in resp_body:  # Keystone errors
+                            message = resp_body['error']['message']
+                            raise exceptions.IdentityError(message)
+                        elif 'message' in resp_body:
+                            message = resp_body['message']
+                    else:
+                        message = resp_body
 
             raise exceptions.ServerFault(message)
 
         if resp.status >= 400:
-            if parse_resp:
-                resp_body = self._parse_resp(resp_body)
-            raise exceptions.RestClientException(str(resp.status))
+            raise exceptions.UnexpectedResponseCode(str(resp.status))
 
     def is_absolute_limit(self, resp, resp_body):
         if (not isinstance(resp_body, collections.Mapping) or
diff --git a/tempest/common/utils/data_utils.py b/tempest/common/utils/data_utils.py
index cd32720..a0a88dd 100644
--- a/tempest/common/utils/data_utils.py
+++ b/tempest/common/utils/data_utils.py
@@ -15,12 +15,8 @@
 
 import itertools
 import random
-import re
-import urllib
 import uuid
 
-from tempest import exceptions
-
 
 def rand_uuid():
     return str(uuid.uuid4())
@@ -57,37 +53,6 @@
     return ':'.join(["%02x" % x for x in mac])
 
 
-def build_url(host, port, api_version=None, path=None,
-              params=None, use_ssl=False):
-    """Build the request URL from given host, port, path and parameters."""
-
-    pattern = 'v\d\.\d'
-    if re.match(pattern, path):
-        message = 'Version should not be included in path.'
-        raise exceptions.InvalidConfiguration(message=message)
-
-    if use_ssl:
-        url = "https://" + host
-    else:
-        url = "http://" + host
-
-    if port is not None:
-        url += ":" + port
-    url += "/"
-
-    if api_version is not None:
-        url += api_version + "/"
-
-    if path is not None:
-        url += path
-
-    if params is not None:
-        url += "?"
-        url += urllib.urlencode(params)
-
-    return url
-
-
 def parse_image_id(image_ref):
     """Return the image id from a given image ref."""
     return image_ref.rsplit('/')[-1]
diff --git a/tempest/exceptions/__init__.py b/tempest/exceptions/__init__.py
index c95f94f..06dee71 100644
--- a/tempest/exceptions/__init__.py
+++ b/tempest/exceptions/__init__.py
@@ -146,3 +146,11 @@
 
 class InvalidHTTPResponseBody(base.RestClientException):
     message = "HTTP response body is invalid json or xml"
+
+
+class InvalidContentType(base.RestClientException):
+    message = "Invalid content type provided"
+
+
+class UnexpectedResponseCode(base.RestClientException):
+    message = "Unexpected response code received"
diff --git a/tempest/services/network/json/network_client.py b/tempest/services/network/json/network_client.py
index 5786ae7..d8c0979 100644
--- a/tempest/services/network/json/network_client.py
+++ b/tempest/services/network/json/network_client.py
@@ -280,6 +280,20 @@
         body = json.loads(body)
         return resp, body
 
+    def add_router_to_l3_agent(self, agent_id, router_id):
+        uri = '%s/agents/%s/l3-routers' % (self.uri_prefix, agent_id)
+        post_body = {"router_id": router_id}
+        body = json.dumps(post_body)
+        resp, body = self.post(uri, body)
+        body = json.loads(body)
+        return resp, body
+
+    def remove_router_from_l3_agent(self, agent_id, router_id):
+        uri = '%s/agents/%s/l3-routers/%s' % (
+            self.uri_prefix, agent_id, router_id)
+        resp, body = self.delete(uri)
+        return resp, body
+
     def list_dhcp_agent_hosting_network(self, network_id):
         uri = '%s/networks/%s/dhcp-agents' % (self.uri_prefix, network_id)
         resp, body = self.get(uri)
diff --git a/tempest/services/network/xml/network_client.py b/tempest/services/network/xml/network_client.py
index 8152d71..daa60da 100644
--- a/tempest/services/network/xml/network_client.py
+++ b/tempest/services/network/xml/network_client.py
@@ -248,15 +248,30 @@
     def list_routers_on_l3_agent(self, agent_id):
         uri = '%s/agents/%s/l3-routers' % (self.uri_prefix, agent_id)
         resp, body = self.get(uri)
-        body = _root_tag_fetcher_and_xml_to_json_parse(body)
+        routers = common.parse_array(etree.fromstring(body))
+        body = {'routers': routers}
         return resp, body
 
     def list_l3_agents_hosting_router(self, router_id):
         uri = '%s/routers/%s/l3-agents' % (self.uri_prefix, router_id)
         resp, body = self.get(uri)
+        agents = common.parse_array(etree.fromstring(body))
+        body = {'agents': agents}
+        return resp, body
+
+    def add_router_to_l3_agent(self, agent_id, router_id):
+        uri = '%s/agents/%s/l3-routers' % (self.uri_prefix, agent_id)
+        router = (common.Element("router_id", router_id))
+        resp, body = self.post(uri, str(common.Document(router)))
         body = _root_tag_fetcher_and_xml_to_json_parse(body)
         return resp, body
 
+    def remove_router_from_l3_agent(self, agent_id, router_id):
+        uri = '%s/agents/%s/l3-routers/%s' % (
+            self.uri_prefix, agent_id, router_id)
+        resp, body = self.delete(uri)
+        return resp, body
+
     def list_dhcp_agent_hosting_network(self, network_id):
         uri = '%s/networks/%s/dhcp-agents' % (self.uri_prefix, network_id)
         resp, body = self.get(uri)
diff --git a/tempest/tests/test_rest_client.py b/tempest/tests/test_rest_client.py
index 9f07972..827b5c9 100644
--- a/tempest/tests/test_rest_client.py
+++ b/tempest/tests/test_rest_client.py
@@ -230,3 +230,114 @@
         data = {"one_top_key": "not_list_or_dict_value"}
         body = self.rest_client._parse_resp(json.dumps(data))
         self.assertEqual(data, body)
+
+
+class TestRestClientErrorCheckerJSON(base.TestCase):
+    c_type = "application/json"
+
+    def set_data(self, r_code, enc=None, r_body=None):
+        if enc is None:
+            enc = self.c_type
+        resp_dict = {'status': r_code, 'content-type': enc}
+        resp = httplib2.Response(resp_dict)
+        data = {
+            "method": "fake_method",
+            "url": "fake_url",
+            "headers": "fake_headers",
+            "body": "fake_body",
+            "resp": resp,
+            "resp_body": '{"resp_body": "fake_resp_body"}',
+        }
+        if r_body is not None:
+            data.update({"resp_body": r_body})
+        return data
+
+    def setUp(self):
+        super(TestRestClientErrorCheckerJSON, self).setUp()
+        self.stubs.Set(config, 'TempestConfigPrivate', fake_config.FakeConfig)
+        self.rest_client = rest_client.RestClient(
+            fake_auth_provider.FakeAuthProvider())
+
+    def test_response_less_than_400(self):
+        self.rest_client._error_checker(**self.set_data("399"))
+
+    def test_response_400(self):
+        self.assertRaises(exceptions.BadRequest,
+                          self.rest_client._error_checker,
+                          **self.set_data("400"))
+
+    def test_response_401(self):
+        self.assertRaises(exceptions.Unauthorized,
+                          self.rest_client._error_checker,
+                          **self.set_data("401"))
+
+    def test_response_403(self):
+        self.assertRaises(exceptions.Unauthorized,
+                          self.rest_client._error_checker,
+                          **self.set_data("403"))
+
+    def test_response_404(self):
+        self.assertRaises(exceptions.NotFound,
+                          self.rest_client._error_checker,
+                          **self.set_data("404"))
+
+    def test_response_409(self):
+        self.assertRaises(exceptions.Conflict,
+                          self.rest_client._error_checker,
+                          **self.set_data("409"))
+
+    def test_response_413(self):
+        self.assertRaises(exceptions.OverLimit,
+                          self.rest_client._error_checker,
+                          **self.set_data("413"))
+
+    def test_response_422(self):
+        self.assertRaises(exceptions.UnprocessableEntity,
+                          self.rest_client._error_checker,
+                          **self.set_data("422"))
+
+    def test_response_500_with_text(self):
+        # _parse_resp is expected to return 'str'
+        self.assertRaises(exceptions.ServerFault,
+                          self.rest_client._error_checker,
+                          **self.set_data("500"))
+
+    def test_response_501_with_text(self):
+        self.assertRaises(exceptions.ServerFault,
+                          self.rest_client._error_checker,
+                          **self.set_data("501"))
+
+    def test_response_500_with_dict(self):
+        r_body = '{"resp_body": {"err": "fake_resp_body"}}'
+        self.assertRaises(exceptions.ServerFault,
+                          self.rest_client._error_checker,
+                          **self.set_data("500", r_body=r_body))
+
+    def test_response_501_with_dict(self):
+        r_body = '{"resp_body": {"err": "fake_resp_body"}}'
+        self.assertRaises(exceptions.ServerFault,
+                          self.rest_client._error_checker,
+                          **self.set_data("501", r_body=r_body))
+
+    def test_response_bigger_than_400(self):
+        # Any response code, that bigger than 400, and not in
+        # (401, 403, 404, 409, 413, 422, 500, 501)
+        self.assertRaises(exceptions.UnexpectedResponseCode,
+                          self.rest_client._error_checker,
+                          **self.set_data("402"))
+
+
+class TestRestClientErrorCheckerXML(TestRestClientErrorCheckerJSON):
+    c_type = "application/xml"
+
+
+class TestRestClientErrorCheckerTEXT(TestRestClientErrorCheckerJSON):
+    c_type = "text/plain"
+
+    def test_fake_content_type(self):
+        # This test is required only in one exemplar
+        # Any response code, that bigger than 400, and not in
+        # (401, 403, 404, 409, 413, 422, 500, 501)
+        self.assertRaises(exceptions.InvalidContentType,
+                          self.rest_client._error_checker,
+                          **self.set_data("405", enc="fake_enc"))
diff --git a/tools/check_logs.py b/tools/check_logs.py
index 98e079a..edf95a1 100755
--- a/tools/check_logs.py
+++ b/tools/check_logs.py
@@ -25,20 +25,24 @@
 import yaml
 
 
-is_neutron = os.environ.get('DEVSTACK_GATE_NEUTRON', "0") == "1"
 is_grenade = (os.environ.get('DEVSTACK_GATE_GRENADE', "0") == "1" or
               os.environ.get('DEVSTACK_GATE_GRENADE_FORWARD', "0") == "1")
 dump_all_errors = True
 
+# As logs are made clean, add to this set
+must_be_clean = set(['c-sch', 'g-reg', 'ceilometer-alarm-notifier',
+                     'ceilometer-collector', 'horizon', 'n-crt', 'n-obj',
+                     'q-vpn'])
+
 
 def process_files(file_specs, url_specs, whitelists):
     regexp = re.compile(r"^.* (ERROR|CRITICAL|TRACE) .*\[.*\-.*\]")
-    had_errors = False
+    logs_with_errors = []
     for (name, filename) in file_specs:
         whitelist = whitelists.get(name, [])
         with open(filename) as content:
             if scan_content(name, content, regexp, whitelist):
-                had_errors = True
+                logs_with_errors.append(name)
     for (name, url) in url_specs:
         whitelist = whitelists.get(name, [])
         req = urllib2.Request(url)
@@ -47,8 +51,8 @@
         buf = StringIO.StringIO(page.read())
         f = gzip.GzipFile(fileobj=buf)
         if scan_content(name, f.read().splitlines(), regexp, whitelist):
-            had_errors = True
-    return had_errors
+            logs_with_errors.append(name)
+    return logs_with_errors
 
 
 def scan_content(name, content, regexp, whitelist):
@@ -122,19 +126,22 @@
                     assert 'module' in w, 'no module in %s' % name
                     assert 'message' in w, 'no message in %s' % name
             whitelists = loaded
-    if process_files(files_to_process, urls_to_process, whitelists):
+    logs_with_errors = process_files(files_to_process, urls_to_process,
+                                     whitelists)
+    if logs_with_errors:
         print("Logs have errors")
-        if is_neutron:
-            print("Currently not failing neutron builds with errors")
-            return 0
-        if is_grenade:
-            print("Currently not failing grenade runs with errors")
-            return 0
-        print("FAILED")
-        return 1
-    else:
-        print("ok")
+    if is_grenade:
+        print("Currently not failing grenade runs with errors")
         return 0
+    failed = False
+    for log in logs_with_errors:
+        if log in must_be_clean:
+            print("FAILED: %s" % log)
+            failed = True
+    if failed:
+        return 1
+    print("ok")
+    return 0
 
 usage = """
 Find non-white-listed log errors in log files from a devstack-gate run.