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6

The Purge is controlled by the PCM with a pulse width modulated switch signal. It is normal for it to cycle rapidly. This allows small amounts of the fuel vapor to be metered into the cylinders. This method allows the system maintain fuel control. One of the main jobs of the evaporative control system purge valve is to maintain a slight negative pressure ...


3

The test connectors are common on Subaru vehicles. They put the car is diagnostic mode and allow for things like the ECU to be reprogrammed. I actually have a Saabaru and had to connect these to use a Cobb Accessport. While it was connected I also had fans and other items turning on and off randomly. Would need some context for the instructions in ...


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In an answer to your linked question, Larry suggests that the indicator light could be coming on due to a loose gas cap, a torn hose or a leaking seal. Remember how the system works: When the right conditions are met IE fuel level between 1/3 and 1/2 tank, outside temp 50 - 90 etc. the ECM pulls a vacuum on the evap system and makes sure it holds a ...


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There are a lot of things that can set this code, so it can be time consuming to figure out, and there are some special tools that make the job a lot easier. You can do it without the special tools, it's just going to take longer. The list below is what it takes to set the code. When VSV for pressure switching valve is ON, ECM judges that there is no ...


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I doubt anything is wrong with your powertrain controller. It sounds like it's doing what it's supposed to, monitoring the EVAP system and throwing codes when it sees a problem. The problem went away or the check engine light would not have gone off. Some trouble codes can be self resolved like that (so many drive cycles without a problem, the light goes ...


2

The cars' computer runs tests on the emission systems on the car. When the car fails the test it turns on the light, if it passes the test after that it turns off the light. You may have something that is close to failing the parameters set by the OEM. A small leak that's just on the edge of passing. Something like temperature changes, or vibration could ...


2

It is most likely a leaking EVAP hose or a leak in the fuel line. Make sure it's nothing obvious like a hose hanging off or a gas cap missing. Also check for a check engine light and have the OBD code read if there is one. There is also a small chance that your fuel pump relay or fuel pump is the cause.


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This situation could be Transmission Flare. The engine control briefly ups the RPM to match the transmission downshifting, to prevent an abrupt downshift feel. If the control or sensing systems are out of whack, it can overdo the RPM adjustment. Some of the items you replaced require adjustment or calibration. For example, the Idle Air Controller (a prime ...


1

I removed the top hose (engine to canister) and drove. I still experienced the run-on, so I believe this conclusively rules out the canister as the cause of the dieseling. I also found that the connection of this top hose to the metal tubing was very loose and possibly the cause of the gasoline smell. I put a hose clamp here to eliminate this. As far as ...


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Yes it can. You can find it as either DORMAN Part # 911603 or as AIRTEX / WELLS Part # 2M1257.


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P1128 code tells you that the engine is running too weak under steady cruising when the EVAP system is checked by the ECU. You need to have an EVAP test to make sure where the fault lies. The fuel tank cap, EVAP vent, purge valves, O2 sensor, exhaust leak, MAP sensor and MAF sensor can all 'fool' the ECU into this code. Remember that the fault codes are what ...


1

The EVAP system prevents excess vacuum and vapor buildup in a sealed fuel tank system. A big difference is the ability of the enhanced system to monitor it's operation. The vehicle will run a vacuum or a pressure test depending on the model and inform the PCM of any leak greater than 0.020 in. (0.5 mm). Certain criteria (the drive cycle) must be met for the ...



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