2007 Vibe.. Engine light comes on, vehicle starts to stall, then continues to run but runs rough. Code shows ignition coil faulty but have replaced, checked plugs,etc. but error continues same problem, although we know it's not.

Hook up a professional grade scan tool to the vehicles computers an check for DTC'S diagnostic trouble codes , that will tell a professional mechanic what to check.

Possible causes
Faulty Ignition Coil 1
Ignition Coil 1 harness is open or shorted
Ignition Coil 1 circuit poor electrical connection
Faulty Engine Control Module (ECM)

What does this mean? When is the code detected? Each ignition circuit is continuously monitored by the Engine Control Module (ECM). The test fails when the ECM does not receive a valid pulse signal from the ignition coil. Possible symptoms Engine Light ON (or Service Engine Soon Warning Light) Lack/Loss of Power Engine may be harder to start Engine hesitation Rough engine idle P0351 TOYOTA Description: The ignition system on the vehicle uses individual ignition coils for each cylinder. The Engine Control Module (ECM) controls each ignition coil operation. The ECM sends a ON/OFF signal to energize the ignition coil to create a spark at the spark plug when a spark is required at the cylinder.

How long since a tune-up?
Are there any applicable trouble codes?
What is year--make--model?

When the light is on have it checked for DTC'S - diagnostic trouble codes , do you know what they are ? Ignition system problem , coil's , plug wires if the vehicle has then . The check engine light code is probably for a engine misfire . Check Engine Light On

The flashing and rough running is to to a misfire or misfires cause by arcing due to moisture on ignition components. Eventually these misfires can lead to other problems such as damage catalytic converter. Start by identifying which cylinder(s) is/are misfiring. The arching can be reproduced with a spray bottle filled with soapy water. Spray the ignition components (wires, coils, distributor cap...)and look for the vehicle to idle rough. Replace any faulty component.

The website has software that looks for obscene words.
I would think a compression test would show if the cylinder is having mechanical problems. And yes the intake or head gasket could be leaking again, especially if the intake or head were warped or cracked.
Have you checked fuel pressure ?
Does the spark plug for cylinder 5 show signs of coolant leaking into the cylinder ?

P0300 - Random Misfire code
P0302 - P0304 and P0307 - Misfire code on cylinder #2, #4 and #7
This description and procedure work in all cylinders failed; A P0302, P0304 and P0307 code means that the the car's computer has detected that one of the engine's cylinders is not firing properly. In this case it's cylinder #2, #4 and #7.


Symptoms may include:
the engine may be harder to start
the engine may stumble / stumble, and/or hesitate
other symptoms may also be present


A code P0302 may mean that one or more of the following has happened:
Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer


Possible Solutions:
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.



P1391 - Rough Road Sensor Performance

Circuit/System Description:
The engine control module (ECM) identifies engine misfire by detecting variations in crankshaft speed. Crankshaft speed variations can also occur when a vehicle is operating over a rough road. The ECM receives a rough road signal by a rough road sensor or an electronic brake control module (EBCM), if equipped with the antilock brake system (ABS). The ABS can detect if the vehicle is on the rough surface based on wheel acceleration/deceleration data supplied by each wheel speed sensor. This information is sent to the ECM by the EBCM through the rough road signal circuit. For vehicles without ABS, the ECM receives a rough road signal from a wheel speed sensor located at the front left wheel. The ECM can determine if the vehicle is on a rough road surface based on the signal from the wheel speed sensor.


Conditions for Running the DTC:
* The vehicle speed is between 5-100 km/h (3.1-62.1 mph).
* The DTC runs continuously when the above conditions are met.


Conditions for Setting the DTC:
The ECM detects that the change in rough road wheel speed sensor signal is less than 2 km/h (1.2 mph) while the change in vehicle speed is greater than 5 km/h (3.1 mph).


Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the B171 Rough Road Sensor.
- Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
* If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
- Ignition ON, test for 0.2-0.8 V between the signal circuit terminal 1 and ground.
* If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
* If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
- If all circuits test normal, replace the B171 Rough Road Sensor.


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Hello I have a 2007 Magnum 2.7L that has code p0302 cylinder#2 misfire seems to have coolant loss but can find no leaks. Recently had another code p0300, so both are active check engine light started flashing but stop and stayed solid. Not driving it. Replaced spark plugs should I replace coils? Any feedback please.

No it will not, you need to have the knocking sound checked out, it could be rod bearing, or timing chain tensioner, both will damage engine, also need to check fuel pressure and ignition coil packs.

Try unplugging the mass air flow sensor or tapping on it when it is running and listen for idle changes.The mass air flow sensor is located on top of the throttle body and is a rectangle held in place by tamper proof torx screws.If you unplug this the engine light will come on but if it stays running while driving then you can be pretty certain this is causing a problem.