subawang Posted February 20, 2008 Posted February 20, 2008 Update!!! See post #36 . . . P0171, P0301, P0302, P0303, P0304. . . These are all the codes my car has thrown over the past month or so. It all started about a month ago. I was sitting at a stoplight on a very cold night (~15 deg), idling and the CEL came on. When it came on, I did not notice the engine running any differently that normal, and continued to drive for the next couple of days expecting for the CEL to disappear. It did, and I thought nothing more of it. A few days later, the CEL came back on again at idle (~15 deg out) and I noticed that it was idling very rough, so much so that even within the cabin it could be felt. But, if I stepped on the throttle at all, the engine revved smoothly. So at that point, I searched the threads here to find out that most likely a vacuum line had blown loose. Since the temperature had been so cold, I did not feel like removing the intercooler to inspect the vacuum hoses. So I simply checked the vacuum lines that I could access which all seemed to be fine. So I then scheduled an appointment with the local subie dealership. I told the service advisor that it had thrown the codes twice on separate occasions when it was very cold out. They ran through their battery of tests, and could not find the cause. So they next called the tech hotline. The tech hotline said that most likely it was due to bad gas. They told this to me at which point I told them I did not think this was the problem. If it was bad gas, shouldn’t the problem manifest itself not only at idle? Anyways, they cleared the codes and I took the car back with instructions to go through a couple tanks of gas and see if the problem went away. As expected, through my next few tanks of gas, the CEL came back on at idle when the ambient temperature was very cold (< 25 deg). Through a few of my own tests, I found that the CEL will turn off (as according to the service manuals) after so many cycles of turning on/off the engine if the code is not thrown again. I found that the engine misfires at idle both cold/warm if the ambient temperature is < 25 deg. This problem does not go away if the engine is warmed up. When the engine is misfiring, if I give it any throttle at all, it will rev smoothly without misfiring. Lastly, even when the ambient temp is < 25 deg, right at start up when the idle control valve/throttle are active to try to warm the engine up, it does not misfire. It only misfires when the engine is trying to do a low speed idle. So, I brought the car back to the dealership two days ago and they have again concluded that the problem is due to bad gas. I finally told them that I would accept the bad gas theory if they would at least convince me that the vacuum lines are intact and connected by pulling the intercooler. My question to you guys is, what should I do next? Although I have already written a book here, I have left out more details for the sake of space. Let me know if you have specific questions. Cliff notes: Engine throwing codes for running lean and misfires on all cylinder only when the amb temp is very cold. Dealership is unable to properly diagnose and give me the “it’s bad gas” cop out.
SBT Posted February 20, 2008 Posted February 20, 2008 P0171 Fuel trim malfunction (A/F too lean) P0301 Cylinder 1 misfire detected P0302 Cylinder 2 misfire detected P0303 Cylinder 3 misfire detected P0304 Cylinder 4 misfire detected You've got fuel-delivery-related issues that are causing misfires on all four cylinders. So I can see their point about it possibly being bad gas (read: water in the fuel), especially if you're getting temporary gas delivery "freeze"at those temps. I don't recommend this due to the harshness of some dry gas products on the fuel system, but perhaps try a can of Dry Gas. Dry gas is essentially ethanol, so I guess you might try E85 if it's available in your area and see if that helps. Good luck and keep us appraised. SBT - Pro amore Dei et patriam et populum -
subawang Posted February 20, 2008 Author Posted February 20, 2008 P0171 Fuel trim malfunction (A/F too lean) P0301 Cylinder 1 misfire detected P0302 Cylinder 2 misfire detected P0303 Cylinder 3 misfire detected P0304 Cylinder 4 misfire detected You've got fuel-delivery-related issues that are causing misfires on all four cylinders. So I can see their point about it possibly being bad gas (read: water in the fuel), especially if you're getting temporary gas delivery "freeze"at those temps. I don't recommend this due to the harshness of some dry gas products on the fuel system, but perhaps try a can of Dry Gas. Dry gas is essentially ethanol, so I guess you might try E85 if it's available in your area and see if that helps. Good luck and keep us appraised. SBT The reason why I don't think its a gas issue is that it doesn't misfire on throttle. Another piece of info; I don't quite reach target boost in 3rd. Boost gauge shows ~13 psi tapering down when I was seeing ~15 psi when it was running good before. I don't have any logs so I can't tell if was severely pulling timing.
outahere Posted February 21, 2008 Posted February 21, 2008 Have you tried different fuels at each fill up?
subawang Posted February 21, 2008 Author Posted February 21, 2008 Have you tried different fuels at each fill up? Prior to this issue, I have been religiously filling up at the Shell down the block from me, V-Power 93 octane. Since the dealership told me to try others, I also tried Mobil (twice) and also BP. The problem continued, again only when the temps dropped below ~25 degrees. I'll update you on the dealership's progress tomorrow. . .I don't have too much hope for them though.
Bbc84 Posted February 21, 2008 Posted February 21, 2008 how many miles? maybe its time for new spark plugs?
subawang Posted February 21, 2008 Author Posted February 21, 2008 how many miles? maybe its time for new spark plugs? About 16k. . .you think all four would go this early? This is on the diagnostic checklist for these engine codes but the dealer (and I for the most part) do not think it is plug/coil pack related. This issue only seems present on very cold days at idle. If it give it any throttle at all, no more misfiring.
reason22 Posted February 21, 2008 Posted February 21, 2008 This is a total shot in the dark, and I'm no expert...but is there an air-temp sensor in/near the MAF that could be broken? I don't know how much the A/F mix changes due to temperature, but if the ECU is getting bad incoming air temp data, maybe it's leaning out the mix erroneously? Just a thought.
subawang Posted February 21, 2008 Author Posted February 21, 2008 This is a total shot in the dark, and I'm no expert...but is there an air-temp sensor in/near the MAF that could be broken? I don't know how much the A/F mix changes due to temperature, but if the ECU is getting bad incoming air temp data, maybe it's leaning out the mix erroneously? Just a thought. I agree, this definitely could be an issue (and is also on the list of diagnotic checks to be performed for these trouble codes). On the first visit to the dealer for this problem, they confirmed that these sensors are operating properly. How they determined that, I do not know. I definitely should ask if they checked these sensors with their scan tool.
ur a bus Posted February 21, 2008 Posted February 21, 2008 Mine started running rough at idle last summer, and idling low all of a sudden. I put my scanner on it, and it had a couple of pending misfire codes (I don't remember which cylinders). I continued driving it, and the "Check Engine" light came on as I pulled into the parking lot at work the next day. It had set a P0171, and had pending P03xx codes for all four cylinders. I looked for any obvious vacuum leaks and found nothing. Using the scanner, the coolant and air temp sensors and MAF checked out OK per the service manual P0171 test. I pulled off the engine cover and started the engine, hoping to hear if there was a vacuum leak. I finally found the "infamous" disconnected vacuum tee under the intercooler. This was the line that is barely visible between the intercooler and the alternator. I was annoyed at the car, but proud of myself for finding the problem --Steve
whitetiger Posted February 21, 2008 Posted February 21, 2008 I bet is a bad O2 sensor. Bad O2s dont always throw O2 codes but if one is giving bad voltage readings, it wil cause the car's closed loop tuning to be off and it will throw misfire and fuel trim codes. However when you go in to open loop the car will run fine since its nut using the readings from the O2 sensor to tune the car. The car will only run poorly during idle and cruise. The car will run fine during warm up, and under load during accell. Im almost cetain that its a O2 sensor problem. This exact problem happened to my Father's 02 Legacy gt. Poor ide and cruise, ran smoth during acceleration, CEL with misfires in all 4 cylinders. Dealer thought it was bad gas too. Changed spark plugs and wires. But it was the O2 sensor.
subawang Posted February 21, 2008 Author Posted February 21, 2008 Mine started running rough at idle last summer, and idling low all of a sudden. I put my scanner on it, and it had a couple of pending misfire codes (I don't remember which cylinders). I continued driving it, and the "Check Engine" light came on as I pulled into the parking lot at work the next day. It had set a P0171, and had pending P03xx codes for all four cylinders. I looked for any obvious vacuum leaks and found nothing. Using the scanner, the coolant and air temp sensors and MAF checked out OK per the service manual P0171 test. I pulled off the engine cover and started the engine, hoping to hear if there was a vacuum leak. I finally found the "infamous" disconnected vacuum tee under the intercooler. This was the line that is barely visible between the intercooler and the alternator. I was annoyed at the car, but proud of myself for finding the problem --Steve UPDATE: Dealer is again returning the car suspecting bad gas. I strongly suggested they pull the intercooler so that they could closely inspect both ends of all vacuum lines and they did, finding nothing. They also supposed ran through the entire diagnostic procedure ending with making a call to the Subaru tech line. This again resulted in the bad gas theory. So at this point, I will go retrieve the car and fill up a few tanks with good gas. I highly suspect that the problem will reoccur (since nothing has changed). I asked the dealer what they would do if it does reoccur, and they did not know. Hopefully at that point, they will at least start throwing parts at her or really going through diagnostics in more detail.
subawang Posted February 21, 2008 Author Posted February 21, 2008 I bet is a bad O2 sensor. Bad O2s dont always throw O2 codes but if one is giving bad voltage readings, it wil case the cars closed loop tuning to be off and it will throw misfire and fuel trim codes. However when you go in to open loop the car will run fine since its nut using the readings from the O2 sensor to tune the car. The car will only run poorly during idle and cruise. The car will run fine during warm up, and under load during accell. Im almost cetain that its a O2 sensor problem. Doesn't hit target boost in 3rd when it goes to open loop. From what I can tell, it only misfires at idle, but not under load at all or when cruising. I don't know how, but my particular problem seems related to temperature, when the ambient temp is < 25 degrees, it shows up. Otherwise, no issue. The only other test I can think of is to see it target boost is hit when temps are warm.
whitetiger Posted February 21, 2008 Posted February 21, 2008 Doesn't hit target boost in 3rd when it goes to open loop. From what I can tell, it only misfires at idle, but not under load at all or when cruising. I don't know how, but my particular problem seems related to temperature, when the ambient temp is < 25 degrees, it shows up. Otherwise, no issue. The only other test I can think of is to see it target boost is hit when temps are warm. right. A bad O2 will only affect idle and cruise, which is why when you step on the gas, it smooths out. What Psi are you hitting in 3rd?
subawang Posted February 21, 2008 Author Posted February 21, 2008 right. A bad O2 will only affect idle and cruise, which is why when you step on the gas, it smooths out. What Psi are you hitting in 3rd? The reason why I don't think its a gas issue is that it doesn't misfire on throttle. Another piece of info; I don't quite reach target boost in 3rd. Boost gauge shows ~13 psi tapering down when I was seeing ~15 psi when it was running good before. I don't have any logs so I can't tell if was severely pulling timing.
reason22 Posted February 22, 2008 Posted February 22, 2008 Well this is a desperate measure, but you could invoke the ol' Lemon Law, depending on the details in your area. From my vague understanding, if a dealer can't fix a car in four visits (and some other detailed requirements) you can legally require them to buy back the car, or swap it for a new one, or somesuch. It would certainly irritate me to have a relatively new car spending so much time at the dealer, with nothing being done. Good luck!
whitetiger Posted February 22, 2008 Posted February 22, 2008 13.5 psi is the factory boost target. i see no problems with hitting boost tagrets.
subawang Posted February 22, 2008 Author Posted February 22, 2008 Well this is a desperate measure, but you could invoke the ol' Lemon Law, depending on the details in your area. From my vague understanding, if a dealer can't fix a car in four visits (and some other detailed requirements) you can legally require them to buy back the car, or swap it for a new one, or somesuch. It would certainly irritate me to have a relatively new car spending so much time at the dealer, with nothing being done. Good luck! I looked into that, but it's a no go. Lemon law in IL is only for cars either 12 months old or less and with 12k or less miles. In the end, I don't really want a new car, just for mine to be fixed. 13.5 psi is the factory boost target. i see no problems with hitting boost tagrets. No argument here, except that when it was running fine, I was hitting 15 psi or so. So, it definitely seems to be running a little off. I think I am starting to hear a slight boost leak. Paying careful attention on my way to work, I can now actually hear my my turbo spool up accompanied with a slight hissing noise (along with a slight misfire at idle today). Definitely not this loud before. I'll keep you guys updated.
subawang Posted March 10, 2008 Author Posted March 10, 2008 Update: I got a survey in the mail in regards to the service that this dealership provided. I filled it in honestly, but with a negative slant and almost immediately received a call from the local service manager. He seemed nice, but upset that I gave some poor remarks. He responded that he wants to make me happy and fix the car. We agreed on a free loaner vehicle and that I could set the exact time for the appointment. I will try and schedule it ASAP and will keep you guys posted.
pillboy Posted March 10, 2008 Posted March 10, 2008 Since they keep claiming "bad gas", I would run it very low and ask them where they would like it filled up at so they can quit blaming it on the gas. It is still ugly.
blackfang Posted March 14, 2008 Posted March 14, 2008 Do you know if they tried to update the ecu at all? [SIZE=1][URL="http://public.fotki.com/blackfang/"]Pics[/URL] [B]08 KawasakiZZR 600- exhaust and other mods 98 Camaro Z/28 HT- some mods......street/strip car 07 Legacy 2.5i- SPT exhaust...daily driver[/B][/SIZE]
subawang Posted March 15, 2008 Author Posted March 15, 2008 They have not tried updating the ecu. Tomorrow should be a cool morning. I will head out to do some datalogging. Hopefully it will be cold enough to misfire.
subawang Posted March 24, 2008 Author Posted March 24, 2008 Well, the dealer called me up the other day and requested that I bring the car in for "decarbonizing" the intake valves. They promised a free loaner. Well, I brought the car in and they did what they said they would. The next day, again, I had still had the misfiring and also a new problem. . . maybe related. I noticed that if I came cruising to a stop in gear and clutched in, that the engine would rev by itself. This does not happen every time, but most of the time. It will rev to about 1500 RPM and stay there until the car comes to a stop. I will attempt to datalog this to figure out if it is a throttle issue or something else. I think this may be related to the misfire . . .
what Posted March 25, 2008 Posted March 25, 2008 I wonder how much money Subaru dealers make from SOA for warranty issue problems.. I cant imagine the dealer is footing the bill for all this work thats done under warranty.
blackfang Posted March 25, 2008 Posted March 25, 2008 If it is a warranty issue, then they fix it(yes warranty rates are less than non warranty). If the tech's misdiagnose, they fix it for free. This is why some dealerships will not make repairs until they can duplicate the problem and know how to fix it. [SIZE=1][URL="http://public.fotki.com/blackfang/"]Pics[/URL] [B]08 KawasakiZZR 600- exhaust and other mods 98 Camaro Z/28 HT- some mods......street/strip car 07 Legacy 2.5i- SPT exhaust...daily driver[/B][/SIZE]
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