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Just got CEL today


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So, today while I was driving my 2008 LGT, I was in intelligent mode, when suddenly it changed to sport and the CEL came on. As of right now, I have the check engine light, traction control light, the for sports mode is blinking, and cruise is blinking. It will nit let me change out os sport mode. What does this mean!? Thanks!
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Your car has a built in code reader for the trouble code trifecta. I tried this one on my 08 and it works.

 

 

http://www.subaruoutback.org/forums/99-do-yourself-illustrated-guides/19053-06-09-how-read-diagnostic-trouble-codes-dtcs.html

 

Yes, this works for 2008 and 2009. It could be a lot of different things, anything from a bad sensor all the way up to a blown engine. If there were no engine symptoms, my money is that something happened with the timing belt. Do not drive the car until you get the code and see what it means. Driving on an engine with bad timing can ruin it quickly.

 

Get the code(s) from this procedure:

 

 

 

Starting condition: key off, headlight switch off.

 

Steps 1 through 7 must be performed within 10 seconds.

 

1. Turn key to ON position. This is the normal running position, the click just before starting, when all the lights on the dash come on, but before you twist to START. Don't start the engine!

 

2. Within 3 seconds, turn the headlight switch ON.

 

3. Press the Trip/Odometer button 4 times.

 

4. Turn the headlight switch OFF.

 

5. Press the Trip/Odometer button 4 times.

 

6. Turn headlight swtich ON.

 

7. Press Trip/Odometer button 4 times. At this point, the DTC display will begin.

 

8. Turn headlight switch OFF. Not necessary for the procedure, but your display may be dimmed and hard to read in bright sunlight. Besides, why drain the battery?

 

The DTCs for each module will display in order: ECM, TCM, ABSCM/VDCCM. Press the Trip/Odometer button to cycle between modules. The FSM states that the display will cycle between modules automatically every three seconds if the button is not pushed, but that did not happen in my car - I had to push the button to cycle the display.

 

For each module, there are three display states:

- Receiving DTC from module (blinking "P" or "C")

- DTC detected & displayed ("P" or "C" followed by 4 digits)

- No DTC found ("P" or "C" followed by "----")

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Note some conditions may cause multiple codes to be stored. They are all important, so don't just go with the first one if there are several.

 

Once you have the codes, there are diagnostic troubleshooting instructions in the factory service manual. Or ask here because we have probably seen most of them at one time or another.

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When you have a CEL some systems are disabled. That may be one of them, a test would be to find some dirt, stop the car, then take off fast and see what happens.

 

I think you need to be more concerned about what caused the CEL.

 

 

http://people.csail.mit.edu/ilh/vacation/

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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This trouble code can be difficult to troubleshoot because it can be caused by a number of different things. It is a generic code, "Catalyst System Efficiency Below Threshold (Bank 1)". Are you sure this is the only trouble code stored? If you are taking it to someone, make sure they go through the troubleshooting procedure in the service manual because just swapping parts can get expensive and time-consuming. Try to figure out what is wrong first before swapping parts. Check for exhaust leaks. Check out the sensor wiring and monitor the oxygen sensors while the car operates which may show a pattern that will narrow down the issue.

 

Don't let people just assume "bad catalytic converter" or "bad oxygen sensors" and start swapping expensive parts to see what happens.

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^^^ What he said. Any competent tech should be able to figure it out for you. There are voltage tolerances for the sensors and if one is out of range, it can throw that code. It is something that has to be monitored real time and also while the car is moving so it would be difficult for us to pinpoint it unless you take a video. If one of the sensors is reading 0 volts then it's a good indication that it could be the culprit.
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  • 5 months later...

Have had several similar issues that are all probably related. Pesky coil crapping out (303/304) now most recently P0420. (Blinking CEL and holy-hell-rough-running w no power)

 

Oddly enough, running on-baord reader following instructions above-

P0303, P0304, P0000

Cycle to next screen

Blinking P never changes

Cycle to next screen

C0071 (Have had recent alignment and the pesky airbag light syndrome too. Tried to reflow soldier with out proper tools. worked for a bit but now back on)

 

Ultimate reason for my post: big question- If a cat is truly going out, wouldn't it run like crap all the time? It's intermittent, and cold start she purrs like a kitten.....

 

These forums are great, plethora of info and experience. Thanks

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Did you fix anything in the last 5 months?

 

Nope. Just the alignment.

 

About 10K (roughly) miles ago new long block. So, plugs/wires/coil were all new.

 

I don't want to be way too wordy so I'll think about timeline of misfires, codes running like sh*t and try to present as succinctly as possible.

 

I just kept thinking if the cat was bad, she'd run terrible all the time.

 

Oh, and 09 Legacy, NA, 5-speed.

 

But it does have a sunroof and she's deep bronze metallic so has that going for her...

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So you cleared the code and it never came back until now? If you never had someone monitor o2/af ratio sensors, fuel trims or even calculated load in some cases, do that first. We can speculate all we want but there's nothing we can do to give you a precise answer.
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Perfectly timed question. As fate would have it, I've got a buddy coming over WED with a fancy-grade scan tool to compile all that data. I'll be sure to post the results.

 

 

No images, my apologies.

 

Cyl #1 wire garbage.

Cyl #4 Plug WAAAY out of gap.

 

Replaced: (warranty :) )

Plugs (gapped 40), wires, coil.

 

Cleared 420, steering angle and pesky airbag. (which obviously came back the moment the car started)

 

Notes: Fuel trims high? +2.3-ish at well warmed idle.

 

Ran the hell out of it. Alternating full load up a long hill and a cruising flat for a few miles, parked, turned off. After some cooling, cycled 3 times. Still no codes.

 

More notes: Still a hair stumbly at idle, but no codes...

 

Gassed up full tank of 92. She's prone to pinging when hot and running 87.

 

Next day, logging mellow freeway miles. About 30 in and CEL lights up. No blink, just on.

 

Pull over and scan codes (appreciate whomever posted that on-board trick)

 

Dreaded P0420....

 

Heard rumors that Subaru can re-image ECU. Will investigate.

 

Next step, inspect and likely replace downstream O2 sensor. Clear code and go from there.

 

Basically I'm looking to avoid replacing cat but will if I have to. (already had the recall cat done several years ago) Fortunately, have access to close to cost and friends to assist with install if needed. And access to a lift certainly never hurts.

 

Summary- New ignition parts, high octane, still stumbly at idle, now 420.

 

There's the update on the brownie. :)

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Update:

 

New plugs/wires/coil/02 sensor.

 

Changed downstream O2 sensor. P0420 had cleared itself by the time I hooked the battery back up. Drove for a couple days, varying loads, varying miles, still stumbly a bit at idle and then today P0420 came back. No other codes.

 

The stumbly idle is a mystery to me. It's "not quite" smooth.

I don't have screen shots of the scan tool info but on a range of -5 to +26 (IIRC) at warm idle the fuel trim was +2.3. Not sure if there's any relevance there.

 

Thank you

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