1996 Legacy Outback 2.5 CEL - Codes P0400 and P0115 - Subaru Outback - Subaru Outback Forums
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post #1 of 3 (permalink) Old 09-15-2011, 01:14 PM Thread Starter
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1996 Legacy Outback 2.5 CEL - Codes P0400 and P0115

Hi - I'm new to the forums here but read them often. Great to finally register.

I've got a 1996 Subaru Legacy Outback (2.5L, Automatic, 168000 miles) with a check engine light that just came on yesterday. I got the codes read and it is reading codes P0400 (EGR System Fault) and P0115 (Engine Coolant Temp Circuit).

The car has been running great lately except for one thing. In the past few weeks, sometimes after driving, turning off the car for a minute to run and do something, and then starting again - the car will sputter a bit and take a second to fully start. Sometimes I've even tapped the gas pedal for a sec and it seems to help it start. This only happens ever once in a while and it seems to be when the car has been running and then I start it again. Car always starts fine first thing in the morning and whenever it has been sitting for more than 30 minutes.

I got the P0400 code about a year ago - my mechanic told me my EGR valve was stuck and that is what triggered it - but he told me not to worry about it and that I didn't need to fix it (he was trying to keep my repair bill limited at the time). He cleared the code and it hasn't come back on and I have driven over 7,000 miles since then.

One other bit of info in case this helps pinpoint a problem - my alternator did die during the middle of the summer while I was driving - the battery ran out of juice and my car began to misfire and sputter since it had no power - and I pulled it over and had it towed and the alternator replaced. When I got my car back the CEL was on - but then it turned off after driving it for about 80 miles or so and never came back on until now. Are these problems related?

Basically my question is - how serious are these codes? Can I make it a few weeks driving it as is? (Student budget is limited) Or am I setting myself up for disaster by not taking it to my mechanic immediately.

Also - what would my estimate cost to repair/replace the EGR valve and/or the Engine Coolant Sensor at a shop?

Thanks! Any help or advice is greatly appreciated!

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post #2 of 3 (permalink) Old 09-15-2011, 04:17 PM
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The EGR valve is a little pricey for the part ($165), but the labor is super fast and easy ... doesn't mean they won't gouge you for it, though. If you're interested in DIYing it, search the forums for P0400 and you'll get lots of good info ... like maybe it's not the EGR valve itself causing the code, but instead could be one or more of several other items. Usually, the EGR valve can also be (carefully) cleaned and reused.

In most cases, a P0400 code will not cause any drive-ability issues ... I drove with it for maybe 50-60k miles before finally fixing it. If you live where they do inspections, you'll need to fix it sooner rather than later.

Can't help with the Engine Coolant Sensor, except there is a fair amount of stuff to move out of the way in order to get to it. See graphic for location on the water pipe. The far left of the pipe is where the upper radiator hose attaches.

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post #3 of 3 (permalink) Old 09-15-2011, 04:31 PM
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they "shouldn't" cause any driveability issues and i can't imagine any impending doom driving them. check engine light stuff is usually not catastrophic or dangerous. make sure it's not running hot, out of oil, and if the check engine light is flashing, that's bad. otherwise, a check engine light is not typically a sign that you're damaging an engine.

i would "guess", but not confidently, that the coolant temp sensor is more likely to cause the no start than the EGR. but i'm sort of borrowing that from older generation stuff where i've seen coolant temp sensors on the engine cause a no start condition and check engine light - i have never seen it in an EJ engine though.

i would not buy the sensors new, just get used ones. someone on here will have them, they don't fail enough or cause major issues to warrant the large expense of new. some coolant temp sensors are reasonable to buy new though, so price tha t out and see.

H6 OBW VDC, H6 OB Sedan, Tribeca, Lifted XT6
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