Scoochiro Posted November 8, 2005 Share Posted November 8, 2005 '02 Forester with 65k miles. Got a CEL and the dealer says replace catalytic converter under warranty. I'm a little bit suspicious because of this particular dealer's reputation, but why wouldn't I let him give me a free cat if that's what the codes indicate? Well, the car now idles rougher and has a tendency to stall out immediately after being started. Sounds possibly like oxygen sensor problem -- could that be related to the catalytic converter work? No new CEL and I'm not sure if the start-then-stall could be related to the sensor or something else. But, I really don't want to just go back and put myself at the dealer's mercy. I want to be armed with some info, if there's any likelihood that they damaged the sensor during the cat install. Thoughts? Quote Link to comment Share on other sites More sharing options...
dustyrider Posted November 9, 2005 Share Posted November 9, 2005 Was the o2 sensor not covered under warranty? Were you asked to replace the sensor or charged for a new one? Cause If in fact the dealer has created a new problem with your car. Perhaps they damaged your 02 sensor or didnt replace with a new one or etc.... They are plugged into your cat. (dont know on the newer cars... pretty easy to find out if you want to crawl under the car and look for the plug that goes into your exhaust.) The computer on your car as well could need to be changed or kicked or whatever it is you do with the newer cars. I drive an 86 Anyways..... Be careful with your approach show confidence in knowledge of your car.(in other words re-search!) Its very possible they messed something up, they can fix easily. You shouldn't have to pay anything.... but to convince them of that! Good Luck:) Quote Link to comment Share on other sites More sharing options...
sea#3 Posted November 9, 2005 Share Posted November 9, 2005 '02 Forester with 65k miles. Got a CEL and the dealer says replace catalytic converter under warranty. I'm a little bit suspicious because of this particular dealer's reputation, but why wouldn't I let him give me a free cat if that's what the codes indicate? Well, the car now idles rougher and has a tendency to stall out immediately after being started. Sounds possibly like oxygen sensor problem -- could that be related to the catalytic converter work? No new CEL and I'm not sure if the start-then-stall could be related to the sensor or something else. But, I really don't want to just go back and put myself at the dealer's mercy. I want to be armed with some info, if there's any likelihood that they damaged the sensor during the cat install. Thoughts? Yes they might have "Desturbed " something in the Front A/F sensor when they swapped the cat and you probably need a new one now Hard call ... was it on the way out? possibly . It's about the age and mileage they tend to go I would suggest they meet you half way , you pay for the part and they install for free ? Odds are if you leave it , it will eventually code up for a PO170 fuel trim code or the stalling and hesitation will get worse SEA#3 Quote Link to comment Share on other sites More sharing options...
Scoochiro Posted November 9, 2005 Author Share Posted November 9, 2005 YHard call ... was it on the way out? possibly . It's about the age and mileage they tend to go SEA#3 I think you are probably about right -- the car ran fine before their work. I guess it may be hard to replace the cat and not run a risk of damaging an already-old O2 sensor, especially if they're physically right next to each other. Still, I'm not sure I should have to pay the full deal. Does a damaged O2 sensor always trigger a CEL, or create a code? I guess I'll just have to check it out, so that I'm not replacing things for no reason, but I'll be that's what's going on here. Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted November 9, 2005 Share Posted November 9, 2005 You are probably right, it was a bad sensor misdiagnosed as bad cat. Typical rookie mistake, wait you said it was a dealer? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted November 9, 2005 Share Posted November 9, 2005 I 'assume' they cleared the ECU? Probably not 'required' with a cat replacement but good insurance after any engine-type work. I dunno Quote Link to comment Share on other sites More sharing options...
idosubaru Posted November 9, 2005 Share Posted November 9, 2005 O2 sensor should be replaced. i wouldn't retain a 65,000 mile O2 sensor after pulling it out. yes it is possible to have sensor related drivability issues without triggering a CEL. car ran fine before they replaced the converter? be helpful to know what code it was flashing that made you take the car in to begin with. also, the O2 sensor may have been unplugged for the converter install, make sure they plugged it back in. older subaru's run perfectly fine (no noticeable difference) with the O2 sensor unplugged, i don't know if the new ones are the same so check to make sure they remember to plug it back in. if there was no problem....someone touched the car....then there was a problem....nearly 100 percent of the time it was "the item touched" causing the problem. since i'm the only one that works on my car, i know from experience! Quote Link to comment Share on other sites More sharing options...
tunered Posted November 9, 2005 Share Posted November 9, 2005 this dont even sound like a 02 sensor problem,take it to one of them free places and let them hook it up and see what it says. Quote Link to comment Share on other sites More sharing options...
Scoochiro Posted November 9, 2005 Author Share Posted November 9, 2005 this dont even sound like a 02 sensor problem,take it to one of them free places and let them hook it up and see what it says. I have to say, this is a great place for advice. Almost as good as my other hangout, Miata.net. I think the above post gets at something I really wondered about. My start-then-stall problem really isn't too commonly assocaited with an O2 sensor failure, is it? I mean, just because the dealer touched the cat and, probably, the O2 sensor, doesn't rule out something else going on. Correlation doesn't mean causation. So, what else does start-then-stall, with a little rougher idle, sound like? I'll read the codes this weekend, of course, but I'm just wondering if these symptoms point to some kind of well-known problem? Thanks much Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted November 9, 2005 Share Posted November 9, 2005 I have to say, this is a great place for advice. Almost as good as my other hangout, Miata.net. I think the above post gets at something I really wondered about. My start-then-stall problem really isn't too commonly assocaited with an O2 sensor failure, is it? I mean, just because the dealer touched the cat and, probably, the O2 sensor, doesn't rule out something else going on. Correlation doesn't mean causation. So, what else does start-then-stall, with a little rougher idle, sound like? I'll read the codes this weekend, of course, but I'm just wondering if these symptoms point to some kind of well-known problem? Thanks much Dude! are you dissin' us? >>>Almost as good as my other hangout, Miata.net.<<< lol! Yeah, I wouldn't rule out engine temp sensor, IAC, TPS stuff. maybe try an ECU reset if you haven't. Quote Link to comment Share on other sites More sharing options...
Scoochiro Posted November 9, 2005 Author Share Posted November 9, 2005 Dude! are you dissin' us? >>>Almost as good as my other hangout, Miata.net.<<< lol! Yeah, I wouldn't rule out engine temp sensor, IAC, TPS stuff. maybe try an ECU reset if you haven't. I wouldn't diss anybody trying to give me free car advice! But, I will note that the fanatics on Miata.net rack up, some of them, 7 - 10 thousand posts before they're really considered "in." By which, I only mean to say, that particular forum is one of the most-supported, heaviest-used of nearly any car-forum I know of. We're good now, aren't we??? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted November 9, 2005 Share Posted November 9, 2005 I wouldn't diss anybody trying to give me free car advice! But, I will note that the fanatics on Miata.net rack up, some of them, 7 - 10 thousand posts before they're really considered "in." By which, I only mean to say, that particular forum is one of the most-supported, heaviest-used of nearly any car-forum I know of. We're good now, aren't we??? yeah we're good! hah! Probably a lot more miatas around than soobs (or maybe the break more often? *****ducking*****) anyway, often subtle changes in a sensor, or a small vacuum leak or something won't throw a CEL. engine temp sensors have been notorious for causing problems related to cold vs warm idling. I wouldn't rule out possible high voltage problems. If you pull plug wires one at a time while the engine is idling roughly, you might locate a cyl. that causes NO diiference when disabled. If so, that cyl may have a bad plug or wire or injector orsome other issue. Subtle and intermittent problems are the worst! I dunno Quote Link to comment Share on other sites More sharing options...
friendly_jacek Posted November 9, 2005 Share Posted November 9, 2005 this dont even sound like a 02 sensor problem,take it to one of them free places and let them hook it up and see what it says. Unfortunately, this is incorrect advice. First, if there is no MIL light, there is NO code to read. Second, faulty o2 sensor (or rather A/F ratio sensor that newer Subs use) CAN cause stalling and hasitation. Read this recent thread: http://www.ultimatesubaru.org/forum/showthread.php?t=45105&page=3&pp=10&highlight=a%2Ff+ratio+sensor I'll repeat: it was likely a bad sensor misdiagnosed as bad cat. C'mon people, we should do better than some lame Miata board! Quote Link to comment Share on other sites More sharing options...
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