AboutTed Ritter Expertise I have more than 26 years experience as toyota technician, I will be able to answer most questions related to the toyota product line up to the present year models, I specialize in difficult to diagnose problems but when posting a question please keep in mind that some situations require the used of special test equipment and diagnostic procedures especially as the newer models become more technologically advanced, so without actually having the car on hand I may only be able to try to steer you in the right direction and in some cases may have to refer you to the toyota dealer but at least you will know what you may be dealing with. Please don't hesitate to ask any questions, I will have an answer for you in most cases. When posting a question keep in mind that I reside in the US, although I get questions from all over the world I may not have an answer for models that are not sold in the US, I will do a reasonable search to try to match your model to the US model,please refrain from asking about diesel powered vehicles, I have no information for them. In most cases I will not answer questions about major modifications of OEM components, engine swapping or aftermarket products,please post a question not a statement, please provide enough basic information such as year, model, what engine and if anything has already been done to fix the problem, the more information I get the more I can help without having to ask you more questions.
Experience Toyota technician since 1979,expert in electrical systems,OBD systems,engine repair, driveability problems,EFI systems,ASE certified,Toyota master technician. Certified Hybrid Vehicle technician.
Education/Credentials Toyota master technician, ASE certified in eight catagories, Hybrid vehicle certified.
Question Hi Ted, a friend of mine has a 1998 Camry, 4 cyl 2.2L, and the check engine light has given me a P0401 code (Insufficient EGR Flow). Without taking anything apart (yet), the EGR seems fine on inspection, it moves with slight pressure and returns to place, vacuum hoses on top seem fine. I've read other causes for this code may be EGR position sensor (I beleive on top of the EGR valve???) or a DPFE sensor (big question mark on this one). My question would be what approach to take to correct this code, and what/where is the DPFE sensor. Your help would be appreciated, thanks!!
Answer The 4 cylinder engine doesn't have a position sensor, the most common cause for this code is the egr modulator valve located directly on the egr valve, in most cases replacing the modulator and the egr vacuum switching valve takes care of the problem.
