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Here's a manual procedure for performing an IAVL:

Disconnect the negative battery terminal for 30 seconds to reset the onboard computer. Do not perform the relearn if the service engine soon light (CEL) is on and codes related to the mass airflow sensor, manifold absolute pressure, or incorrect idle speed are found. If everything is in order, we can begin.

First, bring the engine to normal operating temperature, 160-203°F or 70-95°C. Next turn off all accessories such as the air conditioning, rear window defogger, radio, and heater blower to prevent a load on the engine which would cause erroneous positioning of the throttle plate. Finally, make sure the front wheels of the vehicle are in the neutral position pointing straight ahead. We are now ready to perform the required relearn procedures:
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ACCELERATOR PEDAL RELEASED POSITION LEARNING

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.

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THROTTLE VALVE CLOSED POSITION LEARNING

1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.

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IDLE AIR VOLUME LEARNING

CONDITIONS: Check Engine Light (CEL) with P0507 trouble code and high/pulsating idle, after disconnecting and reconnecting electrical to throttle position controller such as when cleaning throttle body.

Rectangle Font Parallel Pattern Slope


TOOLS NEEDED: stopwatch or timer showing seconds.

1. When engine COLD, first perform the Accelerator Released Position and then the Throttle Valve Closed Position procedure as shown above.
2. Warm up engine at this point. Drive on the road for not less than 10 minutes.
3. Car in Park, turn off all electrical powered stuff, wheels turned straight.
4. Turn key OFF and wait at least 10 seconds.
5. Turn key ON (not ignition) and start stopwatch at same time.
6. When stopwatch is at 3 seconds, press & release accelerator pedal 5 times hard and quickly within 5 seconds.
7. Wait 7 seconds or more and fully press the accelerator pedal and hold for approximately 20 seconds until the check engine light stops blinking and constantly stays on.
(note: If the CEL never starts blinking, then something is not working and you'd better start over again).
8. Within 3 seconds after the check engine light stays constantly on, release the accelerator pedal.
9. Immediately start the engine and let it idle. It may still likely be a high-rev/pulsating idle.
10. Let it run for about 20 seconds, then rev the engine a few times.
11. With foot on brake, shift into Drive. Idle should now go down under 1000 rpm. Shift to Park again, and the car should find its regular idle speed. Operation will be normal except CEL may still be on. It may disappear soon on its own, or you can do the following:

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EASY RESET OF CHECK ENGINE LIGHT (CEL)

1. Turn key OFF and wait at least 10 seconds
2. Turn key ON (no ignition), wait 3 seconds, then press & release accelerator 5x hard and quickly.
3. Wait 10 seconds, then fully press accelerator.
4. After about 12 seconds CEL will go off then start blinking. As soon as it starts blinking, release the accelerator.
5. Wait 10 seconds, then fully press accelerator again.
6. Wait 10 seconds, then release the accelerator again.
7. Turn the key to off, then immediately start the engine. The CEL should be gone now.



Now, here's the big change

  1. Start engine and warm it up to normal operating temperature.
    AND RIDE YOUR CAR FOR AT LEAST 15 MINUTES, this will make for correct
    operating temperatures to happen within the engine for the following
    steps. Warming your car in the garage in the morning aparently does
    not cut it.



    Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.

  1. Turn ignition switch “OFF” and wait at least 10 seconds.

  2. Confirm that accelerator pedal is fully released, turn ignition switch “ON” and wait 3 seconds.

  3. Repeat the following procedure quickly five times within 5 seconds.

  4. Fully depress the accelerator pedal. Fully release the accelerator pedal.

  5. Wait 7 seconds

  6. Fully depress the accelerator pedal and keep it for approx. 20 seconds until the MIL stops blinking and turns ON.

  7. Fully release the accelerator pedal within 3 seconds after the MIL goes off. Start engine and let it idle. THE ENGINE MUST BE
    STARTED WITHIN THE 3 SECONDS AFTER IT STOPS BLINKING, THATS HOW THIS LIGHT GOES OFF. THE SERVICE MANUAL DOES NOT STATE THIS, BUT IF
    YOU LOOK AT THE DIAGRAM WHERE THE ENGINE LINE ON-OFF IS, IT CLEARLY SHOWS YOU SHOULD TURN IT ON
    WITHIN THESE THREE SECONDS.

This is where your engine will start to learn the correct idle settings

  1. Wait 20 seconds.

  2. Rev up the engine two or three times and make sure that idle speed and ignition timing are within the specifications.
 

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Well what i figured would happen happened, the coil didnt alter the performance of the car. I started at cyl #1 and swapped each of the existing coils with the new Denso coil one by one. So im back to the drawing board.
Since you had a P0172 DTC, here are several other things that could cause misfires:
  • The camshaft position sensor or the crankshaft position sensor may be marginal. The best and cheapest fix for this situation is to replace both sensors at the same time; the reason for doing this is there is no way to determine which sensor is at fault with this type of condition. You can take your vehicle to a dealer/repair shop and they'll tell you there is nothing wrong after they go through with diagnostic tests because at that time the vehicle was running OK. You could end up spending $200 or much more depending on how much time/parts are used.
  • Incorrect fuel pressure. Tee-in a temporary fuel pressure gauge between the fuel feed hose and the fuel rail. The readings at idle should be 51 psi.
  • There may be a major intake system vacuum leak. To check the intake system for a vacuum leak, attach a vacuum gauge to a full vacuum source. With the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg. If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. The gasket may have failed; spray a water mist at the gasket to see if the gauge reading changes. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
  • Dirty fuel injector(s). Run some good injection cleaner, like BG products 44K, through the system; give the cleaner about a week or two to do it's job.
 
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