1998 f 150 5.4L Idle Air Control Under speed error...

Intake or vacum leak will be the first codes 174,171, try idle and spray propane around intake if car idles up, then intake is leaking, otherwise could be a broken vacum line, check with a gauge

Here is the code list for the 1990 OBD1 system on your Acura.
Code 0 and 11 Electronic Control Module (ECM)
Code1 Heated oxygen sensor A
Code 2 Oxygen content B
Code 3 and 5 Manifold Absolute Pressure
Code 4 Crank position sensor
Code 6 Engine coolant temperature
Code 7 Throttle position sensor
Code 8 Top dead center sensor
Code 9 No.1 cylinder position sensor
Code 10 Intake air temperature sensor
Code 12 Exhaust recirculation system
Code 13 Barometric pressure sensor
Code 14 Idle air control valve or bad ECM
Code 15 Ignition output signal
Code 16 Fuel Injector
Code 17 Vehicle speed sensor
Code 19 A/T lock-up control solenoid
Code 20 Electric load detector
Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 23 Knock sensor
Code 30 A/T FI signal A
Code 30 A/T FI signal B
Code 41 Heated oxygen sensor heater
Code 43 Fuel supply system
Code 45 Fuel supply metering
Code 48 Heated oxygen sensor
Code 61 Front heated oxygen sensor
Code 63 Rear heated oxygen sensor
Code 65 Rear heated oxygen sensor heater
Code 67 Catalytic converter system
Code 70 Automatic transaxle
Code 71 Misfire detected cylinder 1
Code 72 Misfire detected cylinder 2
Code 73 Misfire detected cylinder 3
Code 74 Misfire detected cylinder 4
Code 75 Misfire detected cylinder 5
Code 76 Misfire detected cylinder 6
Code 80 Exhaust recirculation system
Code 86 Coolant temperature
Code 92 Evaporative emission control system

Hello! Tell me where you placed the jumper wire?...Also is the Check Engine light on?...If it is (See photo below) push a paper clip into the 2 female pins of the OBD 1 connector...Turn on the key and count the Check Engine Light flashes...Example; 5 long flashes followed by 2 short flashes= Code 52...code list below...Guru...saailer

Code 0 and 11 Electronic Control Module (ECM)
Code1 Heated oxygen sensor A
Code 2 Oxygen content B
Code 3 and 5 Manifold Absolute Pressure
Code 4 Crank position sensor
Code 6 Engine coolant temperature
Code 7 Throttle position sensor
Code 8 Top dead center sensor
Code 9 No.1 cylinder position sensor
Code 10 Intake air temperature sensor
Code 12 Exhaust recirculation system
Code 13 Barometric pressure sensor
Code 14 Idle air control valve or bad ECM
Code 15 Ignition output signal
Code 16 Fuel Injector
Code 17 Vehicle speed sensor
Code 19 A/T lock-up control solenoid
Code 20 Electric load detector
Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 23 Knock sensor
Code 30 A/T FI signal A
Code 30 A/T FI signal B
Code 41 Heated oxygen sensor heater
Code 43 Fuel supply system
Code 45 Fuel supply metering
Code 48 Heated oxygen sensor
Code 61 Front heated oxygen sensor
Code 63 Rear heated oxygen sensor
Code 65 Rear heated oxygen sensor heater
Code 67 Catalytic converter system
Code 70 Automatic transaxle
Code 71 Misfire detected cylinder 1
Code 72 Misfire detected cylinder 2
Code 73 Misfire detected cylinder 3
Code 74 Misfire detected cylinder 4
Code 75 Misfire detected cylinder 5
Code 76 Misfire detected cylinder 6
Code 80 Exhaust recirculation system
Code 86 Coolant temperature
Code 92 Evaporative emission control system




I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Hello! See photo below of On Board Diagnostic 1 connector location...Push a paper clip into the two female pins...Turn on the key...The Check Engine Light will flash a two digit code...Example ; 5 long flashes folowed by 2 short flashes= code 52...See list below...When you have the code/codes send a comment...Guru...saailer...



Code 0 and 11 Electronic Control Module (ECM)
Code1 Heated oxygen sensor A
Code 2 Oxygen content B
Code 3 and 5 Manifold Absolute Pressure
Code 4 Crank position sensor
Code 6 Engine coolant temperature
Code 7 Throttle position sensor
Code 8 Top dead center sensor
Code 9 No.1 cylinder position sensor
Code 10 Intake air temperature sensor
Code 12 Exhaust recirculation system
Code 13 Barometric pressure sensor
Code 14 Idle air control valve or bad ECM
Code 15 Ignition output signal
Code 16 Fuel Injector
Code 17 Vehicle speed sensor
Code 19 A/T lock-up control solenoid
Code 20 Electric load detector
Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 23 Knock sensor
Code 30 A/T FI signal A
Code 30 A/T FI signal B
Code 41 Heated oxygen sensor heater
Code 43 Fuel supply system
Code 45 Fuel supply metering
Code 48 Heated oxygen sensor
Code 61 Front heated oxygen sensor
Code 63 Rear heated oxygen sensor
Code 65 Rear heated oxygen sensor heater
Code 67 Catalytic converter system
Code 70 Automatic transaxle
Code 71 Misfire detected cylinder 1
Code 72 Misfire detected cylinder 2
Code 73 Misfire detected cylinder 3
Code 74 Misfire detected cylinder 4
Code 75 Misfire detected cylinder 5
Code 76 Misfire detected cylinder 6
Code 80 Exhaust recirculation system
Code 86 Coolant temperature
Code 92 Evaporative emission control system





I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Hi,

DO NOT replace any more compoents until you have checked your vehicle's OBD computer for fault codes.

1) Run engine until it reaches operating temperature. Turn off engine.

2) Locate the 2-pin connector (BLUE I think it is) under the passenger dashboard, or behind passenger kick panel - this connector could also be mounted into an unused socket ( DO NOT use the 3-pin connector). Using a suitable jumper wire, short these 2 pins together.

3) Turn ignition to ON (but do not start)

4) The Check Engine light will flash the appropriate codes - long flash represents the 1st digit of the code, short flashes represent the 2nd digit of the code, followed by a long pause between codes. e.g. LONG, LONG, SHORT, SHORT, SHORT (long pause) = Code 23 etc.

These are the Honda codes and their meanings:

Code 0 Electronic Control Module (ECM)
Code1 Heated oxygen sensor A
Code 2 Oxygen content B
Code 3 and 5 Manifold Absolute Pressure
Code 4 Crank position sensor
Code 6 Engine coolant temperature
Code 7 Throttle position sensor
Code 8 Top dead center sensor
Code 9 No.1 cylinder position sensor
Code 10 Intake air temperature sensor
Code 11 Electronic Control Module (ECM)
Code 12 Exhaust recirculation system
Code 13 Barometric pressure sensor
Code 14 Idle air control valve or bad ECM
Code 15 Ignition output signal
Code 16 Fuel Injector
Code 17 Vehicle speed sensor
Code 19 A/T lock-up control solenoid
Code 20 Electric load detector
Code 21 V-TEC control solenoid
Code 22 V-TEC pressure solenoid
Code 23 Knock sensor
Code 30 A/T FI signal A
Code 30 A/T FI signal B
Code 41 Heated oxygen sensor heater
Code 43 Fuel supply system
Code 45 Fuel supply metering
Code 48 Heated oxygen sensor
Code 61 Front heated oxygen sensor
Code 63 Rear heated oxygen sensor
Code 65 Rear heated oxygen sensor heater
Code 67 Catalytic converter system
Code 70 Automatic transaxle
Code 71 Misfire detected cylinder 1
Code 72 Misfire detected cylinder 2
Code 73 Misfire detected cylinder 3
Code 74 Misfire detected cylinder 4
Code 75 Misfire detected cylinder 5
Code 76 Misfire detected cylinder 6
Code 80 Exhaust recirculation system
Code 86 Coolant temperature
Code 92 Evaporative emission control system


Hope this helps........

mass air and tps would be 2 most common causes.

P0305 - Cylinder 5 Misfire Detected
P0306 - Cylinder 6 Misfire Detected

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, The Powertrain Control Module (PCM) or Electronic Control Module (ECM) can determine that a misfire is occurring.

When is the code detected?
- Engine Cylinder #5 and #6 is Misfiring.

Symptoms:
- Engine Light ON (or Service Engine Soon Warning Light)
- Lack/loss of power
- Hard start
- Engine hesitation

Possible Causes:
- Improper spark plug at cylinder #5 and #6
- Insufficient compression at cylinder #5 and #6
- Incorrect fuel pressure
- The injector circuit is open or shorted at cylinder #5 and #6
- Fuel injector #5 and #6 may be faulty
- Intake air leak at cyli

Possible Solution:
- Perform Injector Service
- Replaced Spark Plug #5 and #6
- Replaced Injector #5 and #6
- Replaced Ignition Coil #5 and #6

Hope helps.

Generic OBD II Diagnostic Trouble Codes

DTC CODES P0300 to P0399

P0300....Random/Multiple Cylinder Misfire Detected

P0301....Cylinder 1 Misfire Detected

P0302....Cylinder 2 Misfire Detected

P0303....Cylinder 3 Misfire Detected

P0304....Cylinder 4 Misfire Detected

P0305....Cylinder 5 Misfire Detected

P0306....Cylinder 6 Misfire Detected

P0307....Cylinder 7 Misfire Detected

P0308....Cylinder 8 Misfire Detected

P0309....Cylinder 9 Misfire Detected

P0310....Cylinder 10....Misfire Detected

P0311....Cylinder 11 Misfire Detected

P0312....Cylinder 12 Misfire Detected

P0313....Misfire Detected with Low Fuel

P0314....Single Cylinder Misfire (Cylinder not Specified)

P0320....Ignition/Distributor Engine Speed Input Circuit

P0321....Ignition/Distributor Engine Speed Input Circuit Range/Performance

P0322....Ignition/Distributor Engine Speed Input Circuit No Signal

P0323....Ignition/Distributor Engine Speed Input Circuit Intermittent

P0324....Knock Control System Error

P0325....Knock Sensor 1 Circuit (Bank 1 or Single Sensor)

P0326....Knock Sensor 1 Circuit Range/Performance (Bank 1 or Single Sensor)

P0327....Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)

P0328....Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)

P0329....Knock Sensor 1 Circuit Input Intermittent (Bank 1 or Single Sensor)

P0330....Knock Sensor 2 Circuit (Bank 2)

P0331....Knock Sensor 2 Circuit Range/Performance (Bank 2)

P0332....Knock Sensor 2 Circuit Low Input (Bank 2)

P0333....Knock Sensor 2 Circuit High Input (Bank 2)

P0334....Knock Sensor 2 Circuit Input Intermittent (Bank 2)

P0335....Crankshaft Position Sensor A Circuit

P0336....Crankshaft Position Sensor A Circuit Range/Performance

P0337....Crankshaft Position Sensor A Circuit Low Input

P0338....Crankshaft Position Sensor A Circuit High Input

P0339....Crankshaft Position Sensor A Circuit Intermittent

P0340....Camshaft Position Sensor 'A' Circuit (Bank 1 or Single Sensor)

P0341 Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 1 or Single Sensor)

P0342....Camshaft Position Sensor 'A' Circuit Low Input (Bank 1 or Single Sensor)

P0343....Camshaft Position Sensor 'A' Circuit High Input (Bank 1 or Single Sensor)

P0344....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 1 or Single Sensor)

P0345....Camshaft Position Sensor 'A' Circuit (Bank 2)

P0346....Camshaft Position Sensor 'A' Circuit Range/Performance (Bank 2)

P0347....Camshaft Position Sensor 'A' Circuit Low Input (Bank 2)

P0348....Camshaft Position Sensor 'A' Circuit High Input (Bank 2)

P0349....Camshaft Position Sensor 'A' Circuit Intermittent (Bank 2)

P0350....Ignition Coil Primary/Secondary Circuit

P1507 is "Idle Air Control System Underspeed Error". This code indicates a problem with the Idle Air Control (IAC) valve assembly, harness wiring for the IAC or the Powertrain Control Module. So checking the IAC next is the most logical step.

replace the speed idle sensor