diff --git a/locale/circuitpython.pot b/locale/circuitpython.pot
index 504e66a50d..b6e0c7468c 100644
--- a/locale/circuitpython.pot
+++ b/locale/circuitpython.pot
@@ -60,6 +60,11 @@ msgstr ""
 msgid "%%c requires int or char"
 msgstr ""
 
+#: main.c
+#, c-format
+msgid "%02X"
+msgstr ""
+
 #: shared-bindings/rgbmatrix/RGBMatrix.c
 #, c-format
 msgid ""
@@ -2077,6 +2082,10 @@ msgstr ""
 msgid "UART write"
 msgstr ""
 
+#: main.c
+msgid "UID:"
+msgstr ""
+
 #: shared-module/usb_hid/Device.c
 msgid "USB busy"
 msgstr ""
diff --git a/main.c b/main.c
index d8542bcb57..06ca1ba93b 100644
--- a/main.c
+++ b/main.c
@@ -779,9 +779,9 @@ STATIC void __attribute__ ((noinline)) run_boot_py(safe_mode_t safe_mode) {
         #if CIRCUITPY_MICROCONTROLLER && COMMON_HAL_MCU_PROCESSOR_UID_LENGTH > 0
         uint8_t raw_id[COMMON_HAL_MCU_PROCESSOR_UID_LENGTH];
         common_hal_mcu_processor_get_uid(raw_id);
-        mp_printf(&mp_plat_print, "UID:");
-        for (uint8_t i = 0; i < COMMON_HAL_MCU_PROCESSOR_UID_LENGTH; i++) {
-            mp_printf(&mp_plat_print, "%02X", raw_id[i]);
+        mp_cprintf(&mp_plat_print, translate("UID:"));
+        for (size_t i = 0; i < COMMON_HAL_MCU_PROCESSOR_UID_LENGTH; i++) {
+            mp_cprintf(&mp_plat_print, translate("%02X"), raw_id[i]);
         }
         mp_printf(&mp_plat_print, "\n");
         port_boot_info();
diff --git a/ports/atmel-samd/common-hal/busio/I2C.c b/ports/atmel-samd/common-hal/busio/I2C.c
index d97fa227b2..902e696408 100644
--- a/ports/atmel-samd/common-hal/busio/I2C.c
+++ b/ports/atmel-samd/common-hal/busio/I2C.c
@@ -125,8 +125,6 @@ void common_hal_busio_i2c_construct(busio_i2c_obj_t *self,
     // exact cutoff, but no frequency well under 100kHz is available)
     if ((frequency < 95000) ||
         (i2c_m_sync_set_baudrate(&self->i2c_desc, 0, frequency / 1000) != ERR_NONE)) {
-        reset_pin_number(sda->number);
-        reset_pin_number(scl->number);
         common_hal_busio_i2c_deinit(self);
         mp_arg_error_invalid(MP_QSTR_frequency);
     }
diff --git a/py/modbuiltins.c b/py/modbuiltins.c
index 4e9fbfcd93..072ba8675f 100644
--- a/py/modbuiltins.c
+++ b/py/modbuiltins.c
@@ -759,7 +759,6 @@ STATIC const mp_rom_map_elem_t mp_module_builtins_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_KeyError), MP_ROM_PTR(&mp_type_KeyError) },
     { MP_ROM_QSTR(MP_QSTR_LookupError), MP_ROM_PTR(&mp_type_LookupError) },
     { MP_ROM_QSTR(MP_QSTR_MemoryError), MP_ROM_PTR(&mp_type_MemoryError) },
-    { MP_ROM_QSTR(MP_QSTR_MpyError), MP_ROM_PTR(&mp_type_MpyError) },
     { MP_ROM_QSTR(MP_QSTR_NameError), MP_ROM_PTR(&mp_type_NameError) },
     { MP_ROM_QSTR(MP_QSTR_NotImplementedError), MP_ROM_PTR(&mp_type_NotImplementedError) },
     { MP_ROM_QSTR(MP_QSTR_OSError), MP_ROM_PTR(&mp_type_OSError) },
diff --git a/py/obj.h b/py/obj.h
index 8f38a4c7c0..7fa21f5e38 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -742,7 +742,6 @@ extern const mp_obj_type_t mp_type_ReloadException;
 extern const mp_obj_type_t mp_type_KeyError;
 extern const mp_obj_type_t mp_type_LookupError;
 extern const mp_obj_type_t mp_type_MemoryError;
-extern const mp_obj_type_t mp_type_MpyError;
 extern const mp_obj_type_t mp_type_NameError;
 extern const mp_obj_type_t mp_type_NotImplementedError;
 extern const mp_obj_type_t mp_type_OSError;
diff --git a/py/objexcept.c b/py/objexcept.c
index 230f9d11ba..12408c0d1f 100644
--- a/py/objexcept.c
+++ b/py/objexcept.c
@@ -347,7 +347,6 @@ MP_DEFINE_EXCEPTION(UnicodeError, ValueError)
 #if CIRCUITPY_ALARM
 MP_DEFINE_EXCEPTION(DeepSleepRequest, BaseException)
 #endif
-MP_DEFINE_EXCEPTION(MpyError, ValueError)
 /*
   MP_DEFINE_EXCEPTION(Warning, Exception)
     MP_DEFINE_EXCEPTION(DeprecationWarning, Warning)
diff --git a/py/persistentcode.c b/py/persistentcode.c
index 787f724bf6..0431b30a29 100644
--- a/py/persistentcode.c
+++ b/py/persistentcode.c
@@ -582,7 +582,7 @@ mp_raw_code_t *mp_raw_code_load(mp_reader_t *reader) {
         || MPY_FEATURE_DECODE_FLAGS(header[2]) != MPY_FEATURE_FLAGS
         || header[3] > mp_small_int_bits()
         || read_uint(reader, NULL) > QSTR_WINDOW_SIZE) {
-        mp_raise_MpyError(MP_ERROR_TEXT("Incompatible .mpy file. Please update all .mpy files. See http://adafru.it/mpy-update for more info."));
+        mp_raise_ValueError(MP_ERROR_TEXT("Incompatible .mpy file. Please update all .mpy files. See http://adafru.it/mpy-update for more info."));
     }
     if (MPY_FEATURE_DECODE_ARCH(header[2]) != MP_NATIVE_ARCH_NONE) {
         byte arch = MPY_FEATURE_DECODE_ARCH(header[2]);
diff --git a/py/runtime.c b/py/runtime.c
index 7fcad7366a..e5b411b0d3 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -1742,10 +1742,6 @@ NORETURN void mp_raise_OverflowError_varg(const compressed_string_t *fmt, ...) {
     va_end(argptr);
 }
 
-NORETURN void mp_raise_MpyError(const compressed_string_t *msg) {
-    mp_raise_msg(&mp_type_MpyError, msg);
-}
-
 NORETURN void mp_raise_type_arg(const mp_obj_type_t *exc_type, mp_obj_t arg) {
     nlr_raise(mp_obj_new_exception_arg1(exc_type, arg));
 }
diff --git a/py/runtime.h b/py/runtime.h
index a78969780b..923071f7ca 100644
--- a/py/runtime.h
+++ b/py/runtime.h
@@ -225,7 +225,6 @@ NORETURN void mp_raise_BrokenPipeError(void);
 NORETURN void mp_raise_NotImplementedError(const compressed_string_t *msg);
 NORETURN void mp_raise_NotImplementedError_varg(const compressed_string_t *fmt, ...);
 NORETURN void mp_raise_OverflowError_varg(const compressed_string_t *fmt, ...);
-NORETURN void mp_raise_MpyError(const compressed_string_t *msg);
 NORETURN void mp_raise_recursion_depth(void);
 #endif