diff --git a/selfdrive/test/process_replay/process_replay.py b/selfdrive/test/process_replay/process_replay.py
index 0d35f8a910..c75e9aa0a8 100755
--- a/selfdrive/test/process_replay/process_replay.py
+++ b/selfdrive/test/process_replay/process_replay.py
@@ -6,6 +6,7 @@ import heapq
 import signal
 from collections import Counter
 from dataclasses import dataclass, field
+from itertools import islice
 from typing import Any
 from collections.abc import Callable, Iterable
 from tqdm import tqdm
@@ -302,7 +303,7 @@ class ProcessContainer:
         # certain processes use drain_sock. need to cause empty recv to break from this loop
         trigger_empty_recv = False
         if self.cfg.main_pub and self.cfg.main_pub_drained:
-          trigger_empty_recv = next((True for m in self.msg_queue if m.which() == self.cfg.main_pub), False)
+          trigger_empty_recv = any(m.which() == self.cfg.main_pub for m in self.msg_queue)
 
         # get output msgs from previous inputs
         output_msgs = self.get_output_msgs(msg.logMonoTime)
@@ -331,7 +332,7 @@ class ProcessContainer:
 def card_fingerprint_callback(rc, pm, msgs, fingerprint):
   print("start fingerprinting")
   params = Params()
-  canmsgs = [msg for msg in msgs if msg.which() == "can"][:300]
+  canmsgs = list(islice((m for m in msgs if m.which() == "can"), 300))
 
   # card expects one arbitrary can and pandaState
   rc.send_sync(pm, "can", messaging.new_message("can", 1))
@@ -358,19 +359,18 @@ def get_car_params_callback(rc, pm, msgs, fingerprint):
     can = DummySocket()
     sendcan = DummySocket()
 
-    canmsgs = [msg for msg in msgs if msg.which() == "can"]
+    canmsgs = list(islice((m for m in msgs if m.which() == "can"), 300))
     cached_params_raw = params.get("CarParamsCache")
-    has_cached_cp = cached_params_raw is not None
     assert len(canmsgs) != 0, "CAN messages are required for fingerprinting"
-    assert os.environ.get("SKIP_FW_QUERY", False) or has_cached_cp, \
+    assert os.environ.get("SKIP_FW_QUERY", False) or cached_params_raw is not None, \
             "CarParamsCache is required for fingerprinting. Make sure to keep carParams msgs in the logs."
 
-    for m in canmsgs[:300]:
+    for m in canmsgs:
       can.send(m.as_builder().to_bytes())
     can_callbacks = can_comm_callbacks(can, sendcan)
 
     cached_params = None
-    if has_cached_cp:
+    if cached_params_raw is not None:
       with car.CarParams.from_bytes(cached_params_raw) as _cached_params:
         cached_params = _cached_params