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Need help please - 2008 Subaru Legacy - Lost acceleration


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I am really hoping someone can help me please. After reading thru boards and forums my problem could be so many things.

 

The car has lost its acceleration. Even with the pedal on the floor. The RPMs very slowly get up to 2 or 3. On the highway I cannot get past 3K RPM or approx 80 MPH. The RPMs burst up from around 3k and then back down and it keeps doing this if I try to get past 80 or get it to respond quickly if driving slower.

 

The CEL was on and cruise blinking for some time. I disconnected the battery and the CEL has not come back on. The codes were P0113 and P0420. I did what I could afford right now which was clean the air filter and the MAF sensor but no change. Thank you in advance for any help.

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According to this thread, P0113 = Intake Air Temperature Circuit High Input, and P0420 = Catalyst System Efficiency Below Threshold (Bank 1).

 

It's possible that the IAT sensor may need replacing or cleaning. Check out the links above - they might point you in the right direction.

 

Also, did your acceleration come back after clearing the codes?

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I'm guessing you have a 2.5i ?

 

In a GT the IAT is attached to the outside if the MAF tube.

 

2.5i's are known to have cat issues, you may have a bad cat.

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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The cat has to have a 80,000 mile warranty, or so many years, as per government regulations. I know because mine went bad in my 08 Outback 2.5i. If it is a PZEV vehicle they are more prone to these issues because they have more scrubbers in there that clog easier. I know that Subaru will not help if it has more than 80,000 on it, I tried.
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Yes it is 2.5i, I read about the cat but I am not so sure b/c this problem seemed to have started right after my last oil change. Would the CAT going bad have been gradual? I am in west palm beach florida and the legacy has 108k miles. i live far from work.
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Do you have tools ? Can you unbolt the cat and start the car, see if it drives better?

 

You may want to search the web for a cat that will fit your car, the dealer will tell you its over $1000.

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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Did you change the oil, or did someone else? If someone else, I wonder if they inspected the air filter, and maybe that caused a problem. Regardless of what you choose to do, I would wait a few days to see if things return back to normal.

 

Unfortunately Florida doesn't qualify for the 150k emissions warranty.

 

If you do decide to replace the catalytic converter, here are a couple options that I think are allowed in FL.

 

Walker $323.99 on rockauto. There is also a mail in rebate for $50 until 10/31

http://catalog.walkerexhaust.com/catalogPart/walkerPartSearchFromECatalog.do?partKey=989892&partNumber=16564&catalogKey=653&methodName=initialiseWalker&catalogCode=walkerexhaust49state&locale=EN&loadStatus=ACTIVE

 

Eastern Catalytic converter $328.79 on rockauto

http://www.rockauto.com/catalog/moreinfo.php?pk=4698906&cc=1440455

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I got home to check the IAT sensor where I think it is located and found this, see pic.

 

I dont know cars so I don't know what I am looking at. Could this have popped out as a result of a bad cat or something else or could this being so loose be the cause and if so whats the best way to go about fixing it? It is loose enough to fall out with a little tap.

 

Thanks again.

Untitled-1.thumb.jpg.41c04420dcc72de44c64f7617f148287.jpg

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On our non-turbo cars, the intake air temperature sensor is actually part of the maf sensor.

 

The piece that popped out is harmless. I don't understand why it came off and why it won't stay in, but that piece is basically just acts as a stabilizer for the hoses. When you have extra time it wouldn't hurt to try to secure that piece back on with some sort of liquid gasket maker or adhesive.

 

After doing some research, it looks like a malfunctioning maf sensor could cause a p0420 code, but it's really hard to say in your case. Since the problems came out of nowhere, I'm leaning towards the maf sensor being the problem. The problem is both of those codes could cause the problems you're experiencing, a bad maf sensor or a clogged cat by itself could cause poor driving performance.

 

As crazy as it may sound, I would still give the car another day or two, and see if things improve or change.

intakemanifold.thumb.jpg.23ef16bb2029dc008a81ba20d5e8c54b.jpg

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I feel like p0113 is the code I got when I turned my car key to the accessory 2 position with the maf sensor unplugged (as also mentioned in link below). I remember my car drove terrible for the next 2-4 days. I tried everything, cleaned MAF, replaced plugs/wires, reset ecu multiple times, cleaned throttle body. Low and behold one morning I went to start my car, and everything was 100% fixed somehow. That's why I'm a little nervous and reluctant to say start replacing parts.

 

I've attached instructions from the factory service manual on how to troubleshoot the P0113 and the intake air temp sensor. I would just try to get your hands on something that can read the intake air temperature. I would talk to someone at autozone or advance auto parts, I think the code readers they use to diagnose check engine lights for free should be able to read intake air temp.

 

How did you clean your maf sensor earlier?

 

http://legacygt.com/forums/showpost.php?p=4874600&postcount=2

p0113.1.thumb.jpg.a11fae9001cf6ad2e06714da4218da7e.jpg

p0113.2.thumb.jpg.9d50ff12eaa6f986274f1ba6418b7d0c.jpg

p0113.3.thumb.jpg.58c09caf78f2a41599e87abf356fa784.jpg

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You want a direct fit, front catalytic converter. I would look into rockauto.com, their prices are very good and shipping is very reasonable. I suggest a front, direct fit cat because I don't know that you could weld a universal catalytic converter into place where our front cat is. And even if you could, unless you do the work yourself, you're going to end up paying around as much as a direct fit unit would cost at the end.

 

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1440455&parttype=5808

 

In your link..

 

The first item is a front, direct fit catalytic converter. You just bolt it into place, and you're good to go.

 

The second item is a replacement rear catalytic converter. You also just bolt that into place, and you're good to go.

 

The 3rd, 5th, and 6th items are universal catalytic converters. These are designed to be installed in place of your old catalytic converter. You cut out the old catalytic converter, and weld these into place where the old one had been. As far as I know, you really can't do that with the front catalytic converter on our cars.

 

As far as I know, the front catalytic converter is what does most of the work and therefore is likely what has gone bad.

 

Here's a little more information on the subject too.

http://legacygt.com/forums/showthread.php/catalytic-converter-information-129448.html

 

http://www.easterncatalytic.com/education/tech-tips/the-misleading-nature-of-the-po42o-code/

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