Ravenwoods Posted September 6, 2022 Share Posted September 6, 2022 My daughters 95 Legacy, Automatic Transmission, almost 190,000 miles, has had the P0400 code for some time. Comes back almost immediately after I clear it. Engine idles fine, starts fine, runs fine, but very poor gas mileage (140 miles used 3/4 of a tank). So I removed the EGR and transducer yesterday and have been cleaning them. The transducer has a little removeable cap with a spongy filter there and I cleaned that too. I can depress the valve on the EGR and put my finger on that vacuum tube connection and it hold the valve open until I remove my finger. None of the tubes or hoses appear to be blocked. The all seem open. So what about the EGR solenoid? Is there a way to test if that needs replacing? We are preparing the car to sell since she recently bought a 2000 Legacy. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 7, 2022 Share Posted September 7, 2022 The head or tube may be blocked. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 7, 2022 Share Posted September 7, 2022 Keep it as a rental. Weeks rental in Achorage $2600. Crazy. So much for halibut fishing this year. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 7, 2022 Author Share Posted September 7, 2022 (edited) 4 hours ago, lmdew said: The head or tube may be blocked. What is the head? Which tube are you thinking about? So you traveled up from the lower 48 to do halibut fishing? Or you decided not to to go halibut fishing because rentals were too expensive? Did you look at cars on the Turo car rental place? Edited September 7, 2022 by Ravenwoods grammar error Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 7, 2022 Share Posted September 7, 2022 #3 It goes from the egr valve to the cylinder HEAD. 1 Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 7, 2022 Share Posted September 7, 2022 Some good info and troubleshooting. https://www.delphiautoparts.com/usa/en-US/resource-center/basics-egrs-what-they-do-how-they-work-how-troubleshoot Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 7, 2022 Author Share Posted September 7, 2022 7 hours ago, lmdew said: #3 It goes from the egr valve to the cylinder HEAD. Thanks! I'll check it out. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 8, 2022 Author Share Posted September 8, 2022 15 hours ago, lmdew said: #3 It goes from the egr valve to the cylinder HEAD. I found it, a vertical tube about 12 inches long. Nut takes a 17mm wrench. I sprayed some PB blaster fluid on the top one as it doesn't want to turn. It's such a thin nut I'm afraid of the wrench slipping and rounding the nut corners. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 8, 2022 Share Posted September 8, 2022 They can be very tight. I've used a tubing wrench. The flat 6 sides work well. In the yards a vise grip works. Before you go to the trouble of removing it, do the troubleshooting using a hand vacuume pump to open the egr with the engine at idle. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 8, 2022 Author Share Posted September 8, 2022 2 hours ago, lmdew said: They can be very tight. I've used a tubing wrench. The flat 6 sides work well. In the yards a vise grip works. Before you go to the trouble of removing it, do the troubleshooting using a hand vacuume pump to open the egr with the engine at idle. I was thinking I should get a tubing wrench but didn't know the name for it. So I searched Ebay and lots of tubing wrenches from China, England and Australia. So that gave me a clue that maybe they go by a different name here in the USA. Seems they are known as Flare Nut wrenches in the US. Lots them show up in Ebay with shipping from the US. So I ordered one. Quote Link to comment Share on other sites More sharing options...
heartless Posted September 9, 2022 Share Posted September 9, 2022 yeah, flare nut wrenches.. commonly used for brake line work.. probably could have gotten a whole set locally for less money with shipping and all.. most auto parts stores should have them. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 9, 2022 Author Share Posted September 9, 2022 49 minutes ago, heartless said: yeah, flare nut wrenches.. commonly used for brake line work.. probably could have gotten a whole set locally for less money with shipping and all.. most auto parts stores should have them. It was a Craftsman for $6.95 and free shipping. Quote Link to comment Share on other sites More sharing options...
heartless Posted September 9, 2022 Share Posted September 9, 2022 8 hours ago, Ravenwoods said: It was a Craftsman for $6.95 and free shipping. lol, ok, so maybe not, Quote Link to comment Share on other sites More sharing options...
wtdash Posted September 12, 2022 Share Posted September 12, 2022 Hi, I was getting that code and was told by GD on here to check my hoses: "Make sure the vacuum lines for the MAP sensor and MAP sensor switching solenoid are EXACTLY as indicated on the under-hood sticker. " It should be like this: 1 Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 14, 2022 Author Share Posted September 14, 2022 On 9/12/2022 at 11:14 AM, wtdash said: Hi, I was getting that code and was told by GD on here to check my hoses: "Make sure the vacuum lines for the MAP sensor and MAP sensor switching solenoid are EXACTLY as indicated on the under-hood sticker. " It should be like this: Everything appears correct. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 14, 2022 Author Share Posted September 14, 2022 On 9/7/2022 at 5:36 PM, Ravenwoods said: I found it, a vertical tube about 12 inches long. Nut takes a 17mm wrench. I sprayed some PB blaster fluid on the top one as it doesn't want to turn. It's such a thin nut I'm afraid of the wrench slipping and rounding the nut corners. Okay, the tubing spanner or the flare nut wrench arrived this morning and I got the tube off this afternoon. The tube was not blocked and looked rather clean. No partial blockage either. Perhaps with all my cleaning perhaps I've solved the problem. But I would like to make sure the egr solenoid is working. Seems like I saw somewhere how to test that. Also Someone recommended testing the egr with a hand vacuum pump while the car is idling to see if the egr works. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 14, 2022 Author Share Posted September 14, 2022 I found a non-automotive hand vacuum pump that did the job. So at idle when I connect the hand vacuum pump to the EGR it causes the car to idle very badly and almost die. So I guess that means the EGR is working fine? Maybe the system just needed cleaning. I'll get the car insured and take it for a 50 mile drive and see if the P0400 code comes back and see if the gas mileage is back to normal. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 14, 2022 Share Posted September 14, 2022 Valve and line are fine. Could still be the control valve or vaccum hoses. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 14, 2022 Author Share Posted September 14, 2022 3 hours ago, lmdew said: Valve and line are fine. Could still be the control valve or vaccum hoses. None of the vacuum hoses are cracked, but the rubber is old. So maybe the old rubber results in a less than perfect vacuum? What is the control valve? 1 Quote Link to comment Share on other sites More sharing options...
heartless Posted September 14, 2022 Share Posted September 14, 2022 2 hours ago, Ravenwoods said: None of the vacuum hoses are cracked, but the rubber is old. So maybe the old rubber results in a less than perfect vacuum? What is the control valve? yes, old hard rubber does not seal well at all and allows leaks - they dont have to be cracked refresh things with some new vacuum line. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 15, 2022 Share Posted September 15, 2022 Under intake manifold on passenger side. If my memory is correct. Quote Link to comment Share on other sites More sharing options...
Ravenwoods Posted September 15, 2022 Author Share Posted September 15, 2022 1 hour ago, lmdew said: Under intake manifold on passenger side. If my memory is correct. Normally you can find used or new parts on ebay for reasonably prices but nothing came up. Rock Auto also doesn't have this part. There are other sources online but the prices are $80 or more. I might try the local car junk yard. Or I could swap out the one on my 95 Legacy with her 95 Legacy and see if I get a P0400 in my car. 1 Quote Link to comment Share on other sites More sharing options...
heartless Posted September 15, 2022 Share Posted September 15, 2022 i think i would start with the swap.. cheapest course of action and would verify it that is indeed the problem Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 15, 2022 Share Posted September 15, 2022 If you need one, I could dig through parts. Quote Link to comment Share on other sites More sharing options...
lmdew Posted September 15, 2022 Share Posted September 15, 2022 Work with care the hoses will be hard and the plastic barb in the valve is easy to snap off. Yard would be my 1st choice. Quote Link to comment Share on other sites More sharing options...
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