Engine warning light
 

Every day I drive the same route, and at an exact point in the road the check engine light comes on, from a few seconds to a minute, then goes away. The car drives fine and there doesn't seem to be anything wrong. The engine is still warming up a bit, traveling at about 35 mph. The odd thing is it happens at that exact part of the road, no matter how fast I'm driving. I know it isn't anything to be concerned about, but does anyone have any idea as to what would cause it? thanks in advance.

Have you checked to see what codes are stored?

Wasn't there something along these lines happening to someone also? The power lines affecting it or something. Maybe I made that up. I'm almost positive I read about it though. :rolleyes:

no, I haven't checked the codes. Who would have the equipment to check them (anyone besides a dealership?)

Subaru was good enough to us to include a built-in method of checking the codes, here's a link to the instructions:
http://www.subaru-svx.net/photos/files/How-To/14337.doc
And a pic of the connector:
http://www.subaru-svx.net/photos/files/How-To/14369

The how-to locker is a wonderful source of information, particularly since it was cleaned and organized recently.

I've got to say, that is a very strange problem, but given your description of the problem, it sounds like an outside influence on a sensor rather than an actual problem (kind of makes me wonder what else it might be wreaking havoc on when you pass through that point...).

My '92 light goes on after the engine is warmed and sits for a little while. It seems to be the EGR sensor. $80 part, $200 to install (dealer). I'll figure out myself.

<<It seems to be the EGR sensor.>>

Did you get a code for EGR solenoid? I did and it was bad. Replacing it takes some patience, but certainly not $200 worth. Tip: Connect the vacuum lines before bolting it in place.

trouble codes
 

I pulled 3 codes, I don't know if they are recent or not, because its the first time I've checked them and I don't know if they have ever been cleared. I got 56, 32, and 28. According to the list of probable causes this would be the EGR system (56), the right side oxygen sensor (32) and the left side knock sensor (28). What do you think?

I think you should clear the codes and see which ones come back after another day of driving. Then clear them again and check in another week.

clearing codes
 

ok, another problem, I just tried 3 times to clear the codes using the How-to instructions, and they still haven't cleared. Every time I check to see if they are clear it keeps coming back with the same codes.

Codes...Warning Lights
 

BigBlueSVX,


Did you ever get it fixed? What was the problem?

codes...again
 

ok, here is an update.

I cleared the codes and did quite a lot of driving with no problems, but yesterday I noticed the check engine light flicker on a couple times. I checked the codes just now and threw a 28 (left side knock sensor) and a 56 (EGR system), again. Still no problems driving the car.

What should I do next?

Resurrection
 

ok, another update, but with a little more info. I've noticed the check engine light flicker on a couple times recently when driving. The last two codes it threw were for the egr system and the left side knock sensor. I'll check tomorrow to see if any new codes are present. Another thing, lately I've started checking my fuel mileage (which I should have been doing a while ago:rolleyes: ). I don't have a solid figure yet, but it seems my mpg is really crappy. I doubt a knock sensor would cause this (it would only retard the timing, correct?) but maybe the egr system? I'll post as soon as I can check the codes again and fill up the tank. Thanks for any help.

This sounds oddly similar to what mine has been doing as well. I also get crappy fuel mileage (about 14mpg). I will be checking the codes tomorrow and I will post my findings as well...

odd...14 mpg is about what I think I'm getting too. I hope the cure is painless. I'll be interested to see what you find out.

okay, I just checked (according to the directions linked earlier in the thread) and I get nothing. Nada. Zip. The light just keeps blinking over and over at .2 second intervals. According to the directions, that means no codes are stored.

I know I have received CEL conditions several times while driving during the past 6 months. They always went away after a few seconds. Just to be safe, I always pulled off the road and idled, or in one case more recently, shut the car off (the light refused to go off).

Nothing seems wrong besides cruddy mileage, which I was blaming on my failing transmission (manual swap, here I come!). Obvioulsy, something had to make the light go on. The only other thing; my father says the car smells like it is running rich. That would indicate to me something in the emissions control system, like a bad O2 sensor.

The images in the second link in the instructions don't load. Maybe it's just me.

Oh, Big Blue, I just thought of something:

Do you climb a hill at that certain point in your trip when the light comes on? The most recent code I received, the one that wouldn't go off, I was climbing a hill.

Just a thought.

codes
 

I just checked the codes, and there are four. For a recap, the first time I pulled the codes I got a 56, a 32, and a 28. Then I cleared all the codes by removing the battery. The second time I checked, I got a 56 (again), and a 28 (again). I did not clear the codes. Today 56(EGR system) and 28(left side knock sensor) were still there, but there was also 32(again, right side oxygen sensor or circuit) and 37(never seen it before, but its the other oxygen sensor). Very soon, I will know exactly what my mileage is. It may not be as bad as I thought, because I do a lot of "spirited" driving and city, not much on the highway. I'm hoping that one problem is affecting the other systems, hence the other codes. Could one of the oxygen sensors cause all this? I know they don't go out in pairs. Any ideas?

And no, it doesn't come on when going uphill. As far as I can tell, its fairly random (now).

D'oh!
 

That's why I pulled no codes: I disconnected my battery when I swapped in the WRX CD player last week and haven't had a code since. I guess I'll have to wait until it throws another one...

Whatever the case, I'm guessing that the knock sensor isn't a good thing to get...

Oh, and my city mileage sucks, but highway mileage is not too bad. I just got back from a ~1200 mile trip. The last leg of it, I got about 30mpg. That seems about right, no?

So I'm guessing that it is just my failing transmission that sucks up the gas; once it goes into lockup on the highway it seems to be fine.

yeah 30 mpg is actually really good, although I never get that (no highway driving). I assume a knock sensor code would mean that the sensor is sending a signal out of range? I'm betting on one of the oxygen sensors right now, because that would cause crappy mpg, and its a common problem. I guess I can't do much now other than take it to the dealer and have them check the sensors and see if they are working properly?

My light flickers too. It only does it when the engine is warming up. The temperature gauge reaches a certain point, the light dances for me, and then it's gone. I think it happens at the closed loop / open loop transition point. Anyway, I've got latent O2 sensor codes for both of them, but never any current codes. I've been unable to clear the codes, but since the problem only happens for a few seconds, I'm not worried about it.

The bad mileage is normal. :)

hehe, yeah I hope bad mileage is normal. I just filled up the tank, 14.7 mpg. Of course thats city driving, and the occasional spirited driving through the windy roads. I'm going on a 250 mile trip now, so we'll see what the mileage is like then.

If the O2 sensors have not been replaced then now would be the time to change them.

Otherwise start with the code with the lowest number and work your way up from there.

O2 Sensors
 

ok, the symptoms have gotten worse, crappy fuel mileage, loss of power, so I did a search (which I should have done long ago), and I've decided to replace both O2 sensors. I went to www.oxygensensors.com and there were 5 sensors listed. Should I go with a universal? Or should I spend a little more and get one thats plug and play?

If you're driving an SVX then I wouldn't recommend skimping on parts to save a couple dollars.

I agree. Get the most expensive or the exact part you need whenever possible; you likely won't regret it. These cars are like gold-digging girlfriends - they can smell a cheap substitute a mile away, and they'll appreciate it even less...

Oxygen Sensors
 

Yesterday I replaced the two oxygen sensors. I replaced them with the cheapest OEM ones that were available. Not trying to skimp or anything, just kinda low on money at the moment, and I know other people have put in the same sensors without any problems. So far my problems are solved, but I need to go through another tank to see how my fuel mileage is. I did get another code this morning, No. 28 left side knock sensor.

"These cars are like gold-digging girlfriends - they can smell a cheap substitute a mile away, and they'll appreciate it even less..." Ain't that the truth!