Honda Civic 2000 EX

That code is for the idle speed control valve. Please follow the link P0505 Honda Idle Air Control Valve

which engine, options there are many.???
cant fix any engine, until you know what it there.
a civic not Tacoma. as posted.
see end for engines ????

surge 101 (running gasoline?)
it caused by 2 things. (and lots of reasons)
1: engine running lean. all engines lean surge. fix that first.
hint use a scan tool see live data........?????
2: ISC system is faulting, the idle speed controller can fail for #1
or for itself. (it can stick) clean in.


wiki list of engines. (which one???????????????)_
The sixth generation featured engine options were available along with their first Natural Gas Powered Civic, the GX. From 1996-2000 the Civic was sold under the CX, DX, EX, EXR, HX, LX, and for Canada, SE, and Si trims; all base models were made with 1.6L engines. The EX-CX are all SOHC (Honda D engine). The CX, DX, and LX all have D16y7 non-VTEC engines; whereas the EX has a D16y8 VTEC, and the HX has D16y5 VTEC-E. The USDM Si and Canadian SiR came with a DOHC (B16A2 VTEC). The first civic SI coupe EM1 was introduced in 1999 until 2000. Europe saw a DOHC 1.6 VTI hatch and sedan and a DOHC 1.8VTI engine was available for the Domani related five-door liftback and esta
end quote.
I CAN NOT GUESS>!!!

Error Code: P0505
Fault Location:
Idle Speed Control (ISC) System - Malfunction
Possible Cause:
-Wiring harness.
-Idle speed control (ISC) actuator/Idle air control valve (IAC) valve.
-Throttle valve tight/sticking.
-Engine control module (ECM).

Error Code: P0130
Fault:
Oxygen Sensor (O2S) 1, Bank 1 - Circuit Malfunction
Possible Cause:
Malfunction Indicator Lamp (MIL) Triggered on first occurrence.
-Wiring harness.
-Oxygen sensor (O2S).
-Engine control module (ECM).

Error Code: P0505
Fault:
Idle Speed Control (ISC) System - Malfunction
Possible Cause:
-Wiring harness.
-Idle speed control (ISC) actuator/Idle air control valve (IAC) valve.
-Throttle motor.
-Throttle valve tight/sticking.
-Engine control module (ECM).

Error Code: P0100
Fault Location:
-Mass Air Flow (MAF) Sensor/Volume Air Flow (VAF) Sensor - Circuit --Malfunction
Possible Cause:
-Wiring harness.
-Mass air flow (MAF) sensor.
-Volume air flow (VAF) sensor.
-Engine control module (ECM).

Error Code: P1491
Fault:
Exhaust Gas Recirculation (EGR) Valve Insufficient Lift
Possible Cause:
-Wiring harness.
-EGR Valve.
-ECM

Error Code:P1607
Fault:
-Engine Control Module (ECM)/Powertrain Control Module (PCM)

Error Code: P0966
Location:
-Pressure Control (PC) Solenoid B - Circuit Low
Possible Cause:
-Wiring short to earth.
-Pressure control (PC) solenoid.
-Engine control module (ECM)/Powertrain control module -(PCM)/Transmission control module (TCM) .

Code 505 is a problem with the idle air control valve.
Code 309 is noting a cylinder 9 missfire on engines with 10 cylinders which would not include yours. That may be a fluke or not the right number.
Code p1399 is brand specific and for Honda it usually means random miss.
The code 505 could be the idle control valve or a vac leak. The computer can not control idle speed by using the valve.
The miss codes mean the cylinders are not producing power when they should be. Which may or may not be ignition. It could also be fuel or mechanical problems.
If you have not replaced the plugs and done the usual maintenance stuff in the past year or two, I would start with the basics.
Be sure and look at the inside of the dist cap and rotor.

P0505: Idle Air Control Valve System fault, Code P0505
-Vacuum leak
-Dirty throttle body
-IAC motor defective
-Poor electrical connection to the IAC valve, hope this helps and good-day !

per this address "http://www.obd-codes.com/trouble_codes/" p0505 is a "IAC (Idle Air Control) System Malfunction" it gives some good suggestions to look at to find a solution for your problem.

Fix the idle control first, it may be causing the 2nd error code.

P0505: Idle Air Control System

There is a small motor that controls the amount of air the engine gets when you aren't using the throttle. The computer uses this small motor to control your idle. It sounds like it needs to be replaced. You can try cleaning it first with some throttle body & air intake cleaner.

changing the spark plug will not gonna change anything good in the system if i were you,you might check your idle air control valve if functioning right or check you wires goes to it their are possibilities that it might burned up or you might wanna pull out the idle air solenoid they usually tend to have carbon in it cleaning it may resolve the problem sometimes..