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Ron Z.
Ron Z., - Auto Tech -
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Experience:  18+yrs. experience diagnostics & repair of all makes/models.
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SCION XA: scion XA, MIL code P0402. How do I locate DPFE sensor

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scion XA, MIL code P0402. How do I locate DPFE sensor and EGR valve?. How to troubleshoot ?

Hello! Welcome to the site! Thanks for coming! I'm Ron Z. I'm here to provide as much information and insight as I can, to best answer your question.

Where did you get this code from? Was it a generic scan-tool? Can you double-check the code? Are you sure it was P0402 and not P0420?

Customer: replied 3 years ago.

Yes Innova scanner, code 402

Ok. The P0402 is not a valid code for this vehicle. The reason being is first, no Toyota-made vehicle has a "DPFE Sensor". And second, this vehicle does not even have an EGR Valve (or system for that matter). So an EGR-based code of P0402 is completely out of the question here. Any chance I can get you to run to a local AutoZone and have the code re-checked? AutoZone reads p-codes absolutely FREE (except in California).

Customer: replied 3 years ago.

I'// check the code again when I get the car and be back nto you

Sounds good. Get me a valid code, and I'm sure I can help you resolve the issue! Just reply back when you're ready!

Customer: replied 3 years ago.

My son has the car, so I have to wait untill he is back

That's not a problem. I'm off here fairly soon, so if it's not tonight, it'll be first thing in the morning. No worries! I'll be here!

Customer: replied 3 years ago.

Ron, I checked the codes again, since I reset the last code, I had to wait until it came back. The codes now are P0442, P0441, P0446 in that order. Evaporative Emission system leak detected (small leak), Evaporative Emission system incorrect purge flow and Evaporative Emission system vent control syst.

If there is something to replace, can you provide pictures or a link?



DTC P0442 is set by the ECM when there is an evaporative emissions leak from the components within the EVAP System, or when the vapor pressure sensor malfunctions.

DTCs P0441 and P0446 are set by the ECM when there is an evaporative emissions leak from the components within the EVAP System, or when there is a malfunction in either VSV for EVAP and VSV for CCV, or in the vapor pressure sensor itself.

So, with all 3 of these codes set together, the first place I would suggest starting is by having the EVAP System "smoked". This is where a machine forces smoke throught the system and any leaks will reveal themselves with a stream of smoke. If the smoke test shows there are no leaks in the system, then the next item to look into will be the Vapor Pressure Sensor. Carefully inspect all the vacuum lines between the VSV's and Vapor Pressure Sensor looking for any cracks, holes or loose connections (if there were any problems here, the smoke test should have already found it). If the visual inspection checks ok, the VSV's and the Vapor Pressure sensor should be tested and replaced as needed.

Please remember the website WILL NOT automatically compensate me with a part of your deposit or from your subscription WITHOUT YOUR RATING! Please use the Rating System and *Rate My Service* if the information/advice I supplied has helped you. If you have any more questions, use the "Reply" tab – I'm always happy to answer follow-up questions! Follow-ups are always FREE! Even after you rate! Thank-you!

Customer: replied 3 years ago.


Found the problem. A hose was detached from a valve located left of the air filter.I reset the code and hope it does not come back.Thanks for your help.

Awsome! Glad to hear! That was nice and easy! Wish they were all like that! LOL!

Glad I was of some help! Have a great day!
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