diff --git a/CommandStation-EX.ino b/CommandStation-EX.ino
index 61b23ec..92a13aa 100644
--- a/CommandStation-EX.ino
+++ b/CommandStation-EX.ino
@@ -168,7 +168,8 @@ void loop()
     DCCPacket p = dccSniffer->fetchPacket();
     if (p.len() != 0) {
       if (DCCDecoder::parse(p)) {
-	p.print();
+	if (Diag::SNIFFER)
+	  p.print();
       }
     }
   }
diff --git a/DCCDecoder.cpp b/DCCDecoder.cpp
index 6e7d858..f1a0a40 100644
--- a/DCCDecoder.cpp
+++ b/DCCDecoder.cpp
@@ -42,8 +42,10 @@ bool DCCDecoder::parse(DCCPacket &p) {
   for (byte n = 0; n < p.len(); n++)
     checksum ^= d[n];
   if (checksum) {  // Result should be zero, if not it's an error!
-    DIAG(F("Checksum error:"));
-    p.print();
+    if (Diag::SNIFFER) {
+      DIAG(F("Checksum error:"));
+      p.print();
+    }
     return false;
   }
 
diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index 37f67cd..b8c3100 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -1277,6 +1277,10 @@ bool DCCEXParser::parseD(Print *stream, int16_t params, int16_t p[])
         Diag::LCN = onOff;
         return true;
 
+    case "SNIFFER"_hk: // <D SNIFFER ON/OFF>
+        Diag::SNIFFER = onOff;
+        return true;
+
     case "WEBSOCKET"_hk: // <D WEBSOCKET ON/OFF>
         Diag::WEBSOCKET = onOff;
         return true;
diff --git a/StringFormatter.cpp b/StringFormatter.cpp
index 35a4901..641532e 100644
--- a/StringFormatter.cpp
+++ b/StringFormatter.cpp
@@ -29,6 +29,7 @@ bool Diag::ETHERNET=false;
 bool Diag::LCN=false;
 bool Diag::RAILCOM=false;
 bool Diag::WEBSOCKET=false; 
+bool Diag::SNIFFER=false;
 
 
  
diff --git a/StringFormatter.h b/StringFormatter.h
index c046ec7..0407725 100644
--- a/StringFormatter.h
+++ b/StringFormatter.h
@@ -32,7 +32,7 @@ class Diag {
   static bool LCN;
   static bool RAILCOM;
   static bool WEBSOCKET;
-  
+  static bool SNIFFER;
 };
 
 class StringFormatter