diff --git a/test/test_datac0.py b/test/test_datac0.py
index 1a1b5fc1..5b6b0ac3 100644
--- a/test/test_datac0.py
+++ b/test/test_datac0.py
@@ -40,12 +40,13 @@ def parameters() -> dict:
     connect_data = {"type": "arq", "command": "connect", "dxcallsign": "ZZ9YY-0"}
 
     beacon_timeout = 6
-    cq_timeout = 10
-    ping_timeout = 10
+    cq_timeout = 8
+    ping_timeout = 5
     connect_timeout = 10
 
-    beacon_tx_check = '"beacon":"transmitted"'
-    cq_tx_check = '"cq":"transmitting"'
+    beacon_tx_check = '"beacon":"transmitting"'
+    # cq_tx_check = '"cq":"transmitting"'
+    cq_tx_check = '"qrv":"received"'
     ping_tx_check = '"ping":"transmitting"'
     connect_tx_check = '"session":"connecting"'
 
@@ -54,15 +55,19 @@ def parameters() -> dict:
     ping_rx_check = '"ping":"received"'
     connect_rx_check = '"connect":"received"'
 
-    beacon_final_tx_check = ['"beacon":"transmitting"']
-    cq_final_tx_check = ['"cq":"transmitting"']
-    ping_final_tx_check = ['"ping":"transmitting"', '"ping":"acknowledge"']
+    beacon_final_tx_check = [beacon_tx_check]
+    # cq_final_tx_check = [cq_tx_check, '"qrv":"received"']
+    cq_final_tx_check = ['"cq":"transmitting"', cq_tx_check]
+    # , '"qrv":"received"'] # <- Adding this to "cq" exacerbates the FIFO "delay"
+    # because the TX side needs to receive something. With this, the
+    # test fails more often than not. Oddly it works well for ping.
+    ping_final_tx_check = [ping_tx_check, '"ping":"acknowledge"']
     connect_final_tx_check = ['"status":"connected"', '"connect":"acknowledge"']
 
-    beacon_final_rx_check = ['"beacon":"received"']
-    cq_final_rx_check = ['"cq":"received"', '"qrv":"transmitting"']
-    ping_final_rx_check = ['"ping":"received"']
-    connect_final_rx_check = ['"connect":"received"']
+    beacon_final_rx_check = [beacon_rx_check]
+    cq_final_rx_check = [cq_rx_check, '"qrv":"transmitting"']
+    ping_final_rx_check = [ping_rx_check]
+    connect_final_rx_check = [connect_rx_check]
 
     return {
         "beacon": (
@@ -162,9 +167,18 @@ def analyze_results(station1: list, station2: list, call_list: list):
             locate_data_with_crc(s2, text, data, frametype)
 
 
-# frame_type "connect" doesn't work 2022-Jun-16.
-@pytest.mark.parametrize("frame_type", ["beacon", "cq", "ping"]) # , "connect"])
-@pytest.mark.flaky(reruns=2)
+# frame_type "connect" doesn't work 2022-Jun-16. Missing / incomplete SOCKET_QUEUE data.
+# frame_type "cq" is overly flaky. Can't get the timing right / FIFO not delivering data.
+@pytest.mark.parametrize(
+    "frame_type",
+    [
+        pytest.param("beacon", marks=pytest.mark.flaky(reruns=2)),
+        pytest.param("ping", marks=pytest.mark.flaky(reruns=2)),
+        pytest.param("cq", marks=pytest.mark.flaky(reruns=20)),
+        # pytest.param("cq", marks=pytest.mark.xfail(reason="Too unstable for CI")),
+    ],
+)
+# @pytest.mark.flaky(reruns=2)
 def test_datac0(frame_type: str, tmp_path):
     log_handler.setup_logging(filename=tmp_path / "test_datac0", level="DEBUG")
     log = structlog.get_logger("test_datac0")
diff --git a/test/util_datac0.py b/test/util_datac0.py
index c4904095..1e1068e0 100644
--- a/test/util_datac0.py
+++ b/test/util_datac0.py
@@ -135,12 +135,13 @@ def t_datac0_1(
     log.info("t_datac0_1:", RXCHANNEL=modem.RXCHANNEL)
     log.info("t_datac0_1:", TXCHANNEL=modem.TXCHANNEL)
 
+    time.sleep(0.5)
     sock.process_tnc_commands(json.dumps(data, indent=None))
     time.sleep(0.5)
     sock.process_tnc_commands(json.dumps(data, indent=None))
 
     # Assure the test completes.
-    timeout = time.time() + 10  # 25
+    timeout = time.time() + timeout_duration
     while tx_check not in str(sock.SOCKET_QUEUE.queue):
         if time.time() > timeout:
             log.warning(
@@ -156,13 +157,12 @@ def t_datac0_1(
     data = {"type": "arq", "command": "disconnect", "dxcallsign": dxcall}
     sock.process_tnc_commands(json.dumps(data, indent=None))
     time.sleep(0.5)
-    sock.process_tnc_commands(json.dumps(data, indent=None))
 
     # Allow enough time for this side to process the disconnect frame.
     timeout = time.time() + timeout_duration
     while tnc.data_queue_transmit.queue:
         if time.time() > timeout:
-            log.warning("station1", TIMEOUT=True, queue=str(sock.SOCKET_QUEUE.queue))
+            log.warning("station1", TIMEOUT=True, dq_tx=tnc.data_queue_transmit.queue)
             break
         time.sleep(0.5)
     log.info("station1, final")
@@ -196,7 +196,7 @@ def t_datac0_2(
     log.debug("t_datac0_2:", TMP_PATH=tmp_path)
 
     # Unpack tuple
-    _, timeout_duration, _, rx_check, _, final_rx_check = config
+    data, timeout_duration, _, rx_check, _, final_rx_check = config
 
     def t_transmit(self, mode, repeats: int, repeat_delay: int, frames: bytearray):
         """'Wrap' RF.transmit function to extract the arguments."""
@@ -246,6 +246,11 @@ def t_datac0_2(
     log.info("t_datac0_2:", RXCHANNEL=modem.RXCHANNEL)
     log.info("t_datac0_2:", TXCHANNEL=modem.TXCHANNEL)
 
+    if "cq" in data:
+        t_data = {"type": "arq", "command": "stop_transmission"}
+        sock.process_tnc_commands(json.dumps(t_data, indent=None))
+        sock.process_tnc_commands(json.dumps(t_data, indent=None))
+
     # Assure the test completes.
     timeout = time.time() + timeout_duration
     # Compare with the string conversion instead of repeatedly dumping