diff --git a/firmware/controllers/alternatorController.cpp b/firmware/controllers/alternatorController.cpp
index 5c4fdbafd2..9854fa5c28 100644
--- a/firmware/controllers/alternatorController.cpp
+++ b/firmware/controllers/alternatorController.cpp
@@ -26,9 +26,9 @@ EXTERN_ENGINE
 static Logging *logger;
 
 extern pin_output_mode_e DEFAULT_OUTPUT;
+extern engine_pins_s enginePins;
 
 static SimplePwm alternatorControl;
-static OutputPin alternatorPin;
 static pid_s *altPidS = &persistentState.persistentConfiguration.engineConfiguration.alternatorControl;
 static Pid altPid(altPidS, 1, 90);
 
@@ -71,7 +71,7 @@ static msg_t AltCtrlThread(int param) {
 		if (boardConfiguration->onOffAlternatorLogic) {
 			float h = 0.1;
 			bool newState = (vBatt < targetVoltage - h) || (currentPlainOnOffState && vBatt < targetVoltage);
-			alternatorPin.setValue(newState);
+			enginePins.alternatorPin.setValue(newState);
 			currentPlainOnOffState = newState;
 			if (engineConfiguration->debugMode == ALTERNATOR) {
 				tsOutputChannels.debugIntField1 = newState;
@@ -151,12 +151,12 @@ void initAlternatorCtrl(Logging *sharedLogger) {
 		return;
 
 	if (boardConfiguration->onOffAlternatorLogic) {
-		outputPinRegisterExt2("on/off alternator", &alternatorPin, boardConfiguration->alternatorControlPin,
+		outputPinRegisterExt2("on/off alternator", &enginePins.alternatorPin, boardConfiguration->alternatorControlPin,
 				&DEFAULT_OUTPUT);
 
 	} else {
 		startSimplePwmExt(&alternatorControl, "Alternator control", boardConfiguration->alternatorControlPin,
-				&alternatorPin,
+				&enginePins.alternatorPin,
 				engineConfiguration->alternatorPwmFrequency, 0.1, applyAlternatorPinState);
 	}
 	chThdCreateStatic(alternatorControlThreadStack, sizeof(alternatorControlThreadStack), LOWPRIO,
diff --git a/firmware/controllers/idle_thread.cpp b/firmware/controllers/idle_thread.cpp
index cb90711e0c..0acdb5d52b 100644
--- a/firmware/controllers/idle_thread.cpp
+++ b/firmware/controllers/idle_thread.cpp
@@ -40,11 +40,11 @@ static THD_WORKING_AREA(ivThreadStack, UTILITY_THREAD_STACK_SIZE);
 
 static Logging *logger;
 extern TunerStudioOutputChannels tsOutputChannels;
+extern engine_pins_s enginePins;
 EXTERN_ENGINE
 ;
 
 // todo: extract interface for idle valve hardware, with solenoid and stepper implementations?
-static OutputPin idleSolenoidPin;
 static SimplePwm idleSolenoid;
 
 static StepperMotor iacMotor;
@@ -290,7 +290,7 @@ static void initIdleHardware() {
 		/**
 		 * Start PWM for idleValvePin
 		 */
-		startSimplePwmExt(&idleSolenoid, "Idle Valve", boardConfiguration->idle.solenoidPin, &idleSolenoidPin,
+		startSimplePwmExt(&idleSolenoid, "Idle Valve", boardConfiguration->idle.solenoidPin, &enginePins.idleSolenoidPin,
 				boardConfiguration->idle.solenoidFrequency, boardConfiguration->manIdlePosition / 100,
 				applyIdleSolenoidPinState);
 	}
diff --git a/firmware/controllers/injector_central.cpp b/firmware/controllers/injector_central.cpp
index 406ec05951..6e19fd31df 100644
--- a/firmware/controllers/injector_central.cpp
+++ b/firmware/controllers/injector_central.cpp
@@ -222,7 +222,7 @@ static msg_t benchThread(int param) {
 
 extern engine_configuration_s activeConfiguration;
 
-static void unregister(brain_pin_e currentPin, OutputPin *output) {
+void unregister(brain_pin_e currentPin, OutputPin *output) {
 	if (currentPin == GPIO_UNASSIGNED)
 		return;
 	scheduleMsg(logger, "unregistering %s", hwPortname(currentPin));
@@ -232,7 +232,7 @@ static void unregister(brain_pin_e currentPin, OutputPin *output) {
 
 void stopIgnitionPins(void) {
 	for (int i = 0; i < IGNITION_PIN_COUNT; i++) {
-		NamedOutputPin *output = &enginePins.injectors[i];
+		NamedOutputPin *output = &enginePins.coils[i];
 		brain_pin_e currentPin = activeConfiguration.bc.ignitionPins[i];
 		if (engineConfiguration->bc.ignitionPins[i] != currentPin) {
 			unregister(currentPin, output);
diff --git a/firmware/controllers/injector_central.h b/firmware/controllers/injector_central.h
index b81a0ecf40..b3549b883d 100644
--- a/firmware/controllers/injector_central.h
+++ b/firmware/controllers/injector_central.h
@@ -24,6 +24,7 @@ void assertCylinderId(int cylinderId, const char *msg);
 
 void stopInjectionPins(void);
 void startInjectionPins(void);
+void unregister(brain_pin_e currentPin, OutputPin *output);
 
 void stopIgnitionPins(void);
 void startIgnitionPins(void);
diff --git a/firmware/controllers/system/efiGpio.h b/firmware/controllers/system/efiGpio.h
index 1ad52daf87..ab95526edf 100644
--- a/firmware/controllers/system/efiGpio.h
+++ b/firmware/controllers/system/efiGpio.h
@@ -65,6 +65,9 @@ public:
 	OutputPin o2heater;
 //	OutputPin alternatorField;
 	OutputPin errorLedPin;
+	OutputPin idleSolenoidPin;
+	OutputPin alternatorPin;
+
 
 	InjectorOutputPin injectors[INJECTION_PIN_COUNT];
 	NamedOutputPin coils[IGNITION_PIN_COUNT];
diff --git a/firmware/hw_layer/hardware.cpp b/firmware/hw_layer/hardware.cpp
index ddc06b0bdf..b6b9c99606 100644
--- a/firmware/hw_layer/hardware.cpp
+++ b/firmware/hw_layer/hardware.cpp
@@ -51,6 +51,8 @@
 EXTERN_ENGINE
 ;
 extern bool hasFirmwareErrorFlag;
+extern engine_configuration_s activeConfiguration;
+extern engine_pins_s enginePins;
 
 static Mutex spiMtx;
 
@@ -201,13 +203,79 @@ void turnOnHardware(Logging *sharedLogger) {
 #endif /* EFI_SHAFT_POSITION_INPUT */
 }
 
+static void unregisterPin(brain_pin_e currentPin, brain_pin_e prevPin) {
+	if (currentPin != prevPin) {
+		unmarkPin(prevPin);
+	}
+}
+
+void stopSpi(spi_device_e device) {
+	if (!isSpiInitialized[device])
+		return; // not turned on
+	isSpiInitialized[device] = false;
+	unmarkPin(getSckPin(device));
+	unmarkPin(getMisoPin(device));
+	unmarkPin(getMosiPin(device));
+}
+
 void applyNewHardwareSettings(void) {
 #if EFI_SHAFT_POSITION_INPUT || defined(__DOXYGEN__)
 	applyNewTriggerInputPins();
 #endif /* EFI_SHAFT_POSITION_INPUT */
-	stopInjectionPins();
+	
+        // all 'stop' methods need to go before we begin starting pins
+       
+        stopInjectionPins();
 	stopIgnitionPins();
 
+	if (engineConfiguration->bc.is_enabled_spi_2 != activeConfiguration.bc.is_enabled_spi_2)
+		stopSpi(SPI_DEVICE_2);
+
+	if (engineConfiguration->bc.is_enabled_spi_2 != activeConfiguration.bc.is_enabled_spi_2)
+		stopSpi(SPI_DEVICE_3);
+
+
+	{
+		brain_pin_e currentPin = activeConfiguration.bc.fuelPumpPin;
+		if (engineConfiguration->bc.fuelPumpPin != currentPin) {
+			unregister(currentPin, &enginePins.fuelPumpRelay);
+		}
+	}
+	unregisterPin(engineConfiguration->bc.HD44780_rs, activeConfiguration.bc.HD44780_rs);
+	unregisterPin(engineConfiguration->bc.HD44780_e, activeConfiguration.bc.HD44780_e);
+	unregisterPin(engineConfiguration->bc.HD44780_db4, activeConfiguration.bc.HD44780_db4);
+	unregisterPin(engineConfiguration->bc.HD44780_db5, activeConfiguration.bc.HD44780_db5);
+	unregisterPin(engineConfiguration->bc.HD44780_db6, activeConfiguration.bc.HD44780_db6);
+	unregisterPin(engineConfiguration->bc.HD44780_db7, activeConfiguration.bc.HD44780_db7);
+
+	unregisterPin(engineConfiguration->bc.clutchUpPin, activeConfiguration.bc.clutchUpPin);
+
+
+	{
+		brain_pin_e currentPin = activeConfiguration.bc.fanPin;
+		if (engineConfiguration->bc.fanPin != currentPin) {
+			unregister(currentPin, &enginePins.fanRelay);
+		}
+	}
+	{
+		brain_pin_e currentPin = activeConfiguration.bc.idle.solenoidPin;
+		if (engineConfiguration->bc.idle.solenoidPin != currentPin) {
+			unregister(currentPin, &enginePins.idleSolenoidPin);
+		}
+	}
+	{
+		brain_pin_e currentPin = activeConfiguration.bc.alternatorControlPin;
+		if (engineConfiguration->bc.alternatorControlPin != currentPin) {
+			unregister(currentPin, &enginePins.alternatorPin);
+		}
+	}
+	{
+		brain_pin_e currentPin = activeConfiguration.bc.mainRelayPin;
+		if (engineConfiguration->bc.mainRelayPin != currentPin) {
+			unregister(currentPin, &enginePins.mainRelay);
+		}
+	}
+
 	startInjectionPins();
 	startIgnitionPins();
 }
diff --git a/firmware/hw_layer/pin_repository.cpp b/firmware/hw_layer/pin_repository.cpp
index 34a4287a90..eb28f2122a 100644
--- a/firmware/hw_layer/pin_repository.cpp
+++ b/firmware/hw_layer/pin_repository.cpp
@@ -61,6 +61,7 @@ const char *portname(ioportid_t GPIOx) {
 }
 
 static int getPortIndex(ioportid_t port) {
+	efiAssert(port != NULL, "null port", -1);
 	if (port == GPIOA)
 		return 0;
 	if (port == GPIOB)
@@ -79,7 +80,7 @@ static int getPortIndex(ioportid_t port) {
 	if (port == GPIOH)
 		return 6;
 #endif /* defined(STM32F4XX) */
-	firmwareError("portindex");
+	firmwareError("unknown port");
 	return -1;
 }
 
diff --git a/firmware/rusefi.cpp b/firmware/rusefi.cpp
index cff342d312..52160d79c7 100644
--- a/firmware/rusefi.cpp
+++ b/firmware/rusefi.cpp
@@ -284,7 +284,7 @@ void firmwareError(const char *errorMsg, ...) {
 	}
 }
 
-static char UNUSED_RAM_SIZE[1400];
+static char UNUSED_RAM_SIZE[1300];
 
 static char UNUSED_CCM_SIZE[8500] CCM_OPTIONAL;