cman7 Posted September 13, 2009 Share Posted September 13, 2009 My car is a 1997 Subaru Legacy 2.5 GT 4EAT with 178k. So last night I was driving with 4 people in the car and it started bucking. The car has always hesitated from shifting into 2nd to 3rd and has always jumped from 1st to 2nd. It has also developed some knocking in the engine when the car is cold over the past month. Today when I was driving it by myself it started bucking intermittently and then stalled out on me. It started back up and allowed me to bring the car back home but again it was bucking on the way. Any idea what's wrong? I checked the ATF and it's clean and full. Same with the engine oil. I'm pretty sure this thing is done for but I want to see if anyone has any ideas. It has an appointment for my mechanic to look at it on Tuesday. Link to comment Share on other sites More sharing options...
highspeed11 Posted September 17, 2009 Share Posted September 17, 2009 Any update? From the symptoms I would say check the MAF? Link to comment Share on other sites More sharing options...
Jonathan Posted September 17, 2009 Share Posted September 17, 2009 While a "bad" Mass Air flow (MAF) sensor is certainly possible it could easily be a simple ignition or fuel problem as well. If you have not had a recent tune up with quality parts, replace the spark plugs (with either Denso or preferably NGK brand - do NOT use BOSCH or Champion), and replace the spark plug wires. You may need to replace the coil packs (located on top of the intake manifold). Replacing these parts should cure most simple ignition issues. Replacing the fuel filter is a good idea as well (although it could also be a failing fuel pump). My vote would be to replace the cheaper common parts first and then look at a new set of ignition coil packs, and in tank fuel pump. You can purchase a can of MAF sensor cleaner cheaply and see if it does any good. You might also need to replace the oxygen sensors, or even the catalitic converter although you would likely be seeing a "Check Engine" light alerting you to a problem if you needed to replace these parts. Link to comment Share on other sites More sharing options...
cman7 Posted September 17, 2009 Author Share Posted September 17, 2009 Any update? From the symptoms I would say check the MAF? I took it to my mechanic and he said nothing was wrong. I took it home and it didn't seem to act up. I'm still a little concerned the car is going to leave me stranded somewhere though. While a "bad" Mass Air flow (MAF) sensor is certainly possible it could easily be a simple ignition or fuel problem as well. If you have not had a recent tune up with quality parts, replace the spark plugs (with either Denso or preferably NGK brand - do NOT use BOSCH or Champion), and replace the spark plug wires. You may need to replace the coil packs (located on top of the intake manifold). Replacing these parts should cure most simple ignition issues. Replacing the fuel filter is a good idea as well (although it could also be a failing fuel pump). My vote would be to replace the cheaper common parts first and then look at a new set of ignition coil packs, and in tank fuel pump. You can purchase a can of MAF sensor cleaner cheaply and see if it does any good. You might also need to replace the oxygen sensors, or even the catalitic converter although you would likely be seeing a "Check Engine" light alerting you to a problem if you needed to replace these parts. A full tune up was performed in January when I bought the car. I've driven about 14k since then. Spark plugs, wires, coil pack, fuel filter, pcv valve, air filter were all replaced during that time. I did have a CEL for the cat for a while but it went away back in March and hasn't been a problem ever since. I haven't had any issues since I've gotten the car back, so we'll see if it starts to give me trouble again. Link to comment Share on other sites More sharing options...
Jonathan Posted September 18, 2009 Share Posted September 18, 2009 One of the obvious questions to ask is does it start "bucking" or "knocking" at a certain temperature or RPM range ? I am thinking that "bucking" could be either fuel or ignition, but that "knocking" is almost certainly an ignition issue. You mentioned the full tune up done back when you bought the car. Do you know what brand of spark plugs they used back then ? 14K sounds about right for a set of plugs to start carbon fouling (especially if they weren't Denso or NGK). It wouldn't hurt to pull one or more plugs just to check on their condition. Link to comment Share on other sites More sharing options...
cman7 Posted September 18, 2009 Author Share Posted September 18, 2009 One of the obvious questions to ask is does it start "bucking" or "knocking" at a certain temperature or RPM range ? I am thinking that "bucking" could be either fuel or ignition, but that "knocking" is almost certainly an ignition issue. You mentioned the full tune up done back when you bought the car. Do you know what brand of spark plugs they used back then ? 14K sounds about right for a set of plugs to start carbon fouling (especially if they weren't Denso or NGK). It wouldn't hurt to pull one or more plugs just to check on their condition. It does which is quite odd to me. When cold the engine knocks. About 10-15 mins into driving it starts the bucking/stalling. When I got home last night I let the car run for a while while in drive, holding the brake of course. Definitely sounds like its trying to stall. The knocking is a lot more prevalent now even when warm/hot. I think I'm going to pull the plugs and check the condition. I'd bet they used cheap ones. I just don't want to spend much money on a dying engine. Link to comment Share on other sites More sharing options...
cman7 Posted September 21, 2009 Author Share Posted September 21, 2009 So when this all started I purchased a 1/2 a tank of gas at a local citgo station. When that ran out I bought some gas at irving, like i normally do, and it all went away. Runs perfectly fine now. It's hard for me to believe bad gas could cause such a ruckus. Thanks for the help! Link to comment Share on other sites More sharing options...
eekay Posted September 21, 2009 Share Posted September 21, 2009 Bad gas can most certainly cause a nasty amount of issues. I've had bad gas experiences myself. Luckily, none of them happened to cause any permanent damage. One of my friends had to have an entire engine swap over some bad 7/11 gas about 6 years ago. 7/11 paid for it, of course, but she was still car-less for about 1.5 weeks. My 9.3 cups EJ22 makes me feel like my **** is 2.8 decimeters! Link to comment Share on other sites More sharing options...
cman7 Posted September 21, 2009 Author Share Posted September 21, 2009 Bad gas can most certainly cause a nasty amount of issues. I've had bad gas experiences myself. Luckily, none of them happened to cause any permanent damage. One of my friends had to have an entire engine swap over some bad 7/11 gas about 6 years ago. 7/11 paid for it, of course, but she was still car-less for about 1.5 weeks. Honestly, when I heard people said bad gas before I really thought it was in their head. I couldn't imagine how a certain "batch" of gas could be bad That is until I experience it myself. I really had no idea it could cause such a stir. I hope nothing is damaged. I'm doubting citgo would cover anything. ....Reminds me. This was the same place that I went to wash my car and they shut the power off before i could rinse. Imagine going to wash your car at 8:45PM getting all the soap on it and then not being able to take it off. Yup that's what happened. They couldn't and wouldn't turn it back on because they armed the alarm for the building. Link to comment Share on other sites More sharing options...
cman7 Posted September 21, 2009 Author Share Posted September 21, 2009 ...not to mention I had 4 dollars worth of quarters I lost in the machine. Link to comment Share on other sites More sharing options...
eekay Posted September 21, 2009 Share Posted September 21, 2009 I'd say that Citgo is to be avoided from this day forward. My 9.3 cups EJ22 makes me feel like my **** is 2.8 decimeters! Link to comment Share on other sites More sharing options...
cman7 Posted September 21, 2009 Author Share Posted September 21, 2009 I would agree. Link to comment Share on other sites More sharing options...
cman7 Posted September 28, 2009 Author Share Posted September 28, 2009 So what I thought to be bad gas.... wasn't I put some more irving gas in when that tank of the other irving gas was done with. Car drove fine for all of the last tank and 1/2 of this tank. It started raining last night as I was heading home, about 4AM, when the car started acting like it had low power. I was going up hill. Car started bucking and trying to stall again. I pulled over and it stalled. Parked it for the night. So this afternoon I go to get the car and it started but stalled again 5 minutes down the road again. Note: it was raining again today. I go back home and do some research. The CEL came on for my Catylitic Converter at the beginning of last week. It came on last January when i bought the car and went away in the spring. I thought maybe the Cat was causing these issues. ....excerpt from 2carpros.com Because of the extreme temperatures the catalytic converter produces the catalyst material can crack and come apart clogging the outlet port of the converter causing low power and stalling. So upon reading this supporting information I thought since I need a new Cat anyway I might as well try drilling some holes just before it so the exhaust from the engine can escape and not be clogged in the cat. I started it and it ran rough. Shut it off. Started it again and it ran fine. I thought I had fixed it. Drove it down the road about a 1/4 of a mile and it started to have low power and stalled again. So I had to have the car towed since it's in a 2 hour parking space. And since it's a Sunday night the towing costs extra. Very, very pissed at the car right now. Link to comment Share on other sites More sharing options...
cman7 Posted September 28, 2009 Author Share Posted September 28, 2009 I had all intentions on buying a Stromung High flow cat. Just wanted to avoid towing and to make the car driveable, but loud, for the week while I waited for it to come in. But it appears the problem might be something else regardless of the CEL. Link to comment Share on other sites More sharing options...
cman7 Posted September 28, 2009 Author Share Posted September 28, 2009 I'm thinking it might be possible that the first cat might be failing. I drilled the holes in between cat #1 and cat #2 http://i87.photobucket.com/albums/k148/coreboy7/suby/exhaust.jpg Link to comment Share on other sites More sharing options...
eekay Posted September 28, 2009 Share Posted September 28, 2009 You didn't drill before both cats? Drill upstream of both cats (But try to avoid upstream of the O2 sensor) and see if it releases better. Has it been wet/raining every time this has happened? If so, there could very well be some sort of computer/ECU components under the hood getting wet. How much rust do you have under the car? Are there any rust spots on the underside of the passenger front seat where the ECU sits? Any holes in your firewall that could allow moisture to the passenger floor? My 9.3 cups EJ22 makes me feel like my **** is 2.8 decimeters! Link to comment Share on other sites More sharing options...
cman7 Posted September 28, 2009 Author Share Posted September 28, 2009 You didn't drill before both cats? Drill upstream of both cats (But try to avoid upstream of the O2 sensor) and see if it releases better. Has it been wet/raining every time this has happened? If so, there could very well be some sort of computer/ECU components under the hood getting wet. How much rust do you have under the car? Are there any rust spots on the underside of the passenger front seat where the ECU sits? Any holes in your firewall that could allow moisture to the passenger floor? I didn't. I felt like a ricer with one hole drilled. It hasn't been raining every time this has happened, however the first time it occured i drove through a fairly large puddle. I looked in the engine bay each time though it was relitively dry. The car was undercoated when i bought it with rubberized undercoating so no rust underneath. At least no substantial rust. Link to comment Share on other sites More sharing options...
cman7 Posted September 28, 2009 Author Share Posted September 28, 2009 The guy looking at it just called earlier actually. The MAF sensor had to be replaced. It was apparently throwing that code as well. The autozone tech didn't know what he was doing when he read the code(s). I wish they would let you do it. He also patched the holes drilled and it's ready to go. I still need to buy a cat though. They wanted to charge me 600 bucks for an OEM one. I'm going to buy a stromung high flow cat for 400 on boxer4racing.com within the next few weeks. That is unless i can find one for cheaper. Thanks again for the help! Link to comment Share on other sites More sharing options...
eekay Posted September 29, 2009 Share Posted September 29, 2009 Nice! Hopefully the situation is taken car of! I actually have a couple of high-flow cats sitting around that I won't be doing anything with any time soon. If you want one (or both) feel free to let me know. They each have about 3K miles on them so they're pretty damn new. I forget the brand, but they worked quite well on my 2.5GT. I paid about $750 for the 2 cats and a bit of cat-back work as well. Cats are expensive. I'll get rid of these for like... $150 each + shipping? My 9.3 cups EJ22 makes me feel like my **** is 2.8 decimeters! Link to comment Share on other sites More sharing options...
highspeed11 Posted September 29, 2009 Share Posted September 29, 2009 Hmm... So it was the MAF afterall? Why do you still need a cat? Link to comment Share on other sites More sharing options...
cman7 Posted September 29, 2009 Author Share Posted September 29, 2009 Nice! Hopefully the situation is taken car of! I actually have a couple of high-flow cats sitting around that I won't be doing anything with any time soon. If you want one (or both) feel free to let me know. They each have about 3K miles on them so they're pretty damn new. I forget the brand, but they worked quite well on my 2.5GT. I paid about $750 for the 2 cats and a bit of cat-back work as well. Cats are expensive. I'll get rid of these for like... $150 each + shipping? It seems to be running fine today. I did notice however that the car idles higher when in park and warmed up. And the knocking appears to have either gone away or become less prevalent. If you can figure out what brand the cats are I may have to take you up on that. Send me a PM if you need to. Hmm... So it was the MAF afterall? Why do you still need a cat? It's still throwing a code for the cat. I was told the platinum screen is broken but it hasn't quite crumpled and caused a problem yet. But as far as running goes the MAF appears to have solved the problem. Link to comment Share on other sites More sharing options...
eekay Posted September 29, 2009 Share Posted September 29, 2009 It seems to be running fine today. I did notice however that the car idles higher when in park and warmed up. And the knocking appears to have either gone away or become less prevalent. If you can figure out what brand the cats are I may have to take you up on that. Send me a PM if you need to. No problem. I'll take a look at them this weekend as they're in my friend's garage where I do all my work. I'll let you know for sure though. My 9.3 cups EJ22 makes me feel like my **** is 2.8 decimeters! Link to comment Share on other sites More sharing options...
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