05 LGT codes help

Getting extremely frustrated.

Car runs like crap barely idles.

Have tried 2 shops and no one know except to charge me for Diagnostics and change useless items.

Replaced cat, 2 coils , plugs, air filter...

Here are the new codes from Torque,

 

Vehicle Manufacturer: Subaru 2005 legacy gt

Vehicle Calibration ID: A2WC510C

AD3A104A

Current Fault Log

------------------

P0102: Mass or Volume Air Flow Circuit Low Input

P0301: Cylinder 1 Misfire Detected

P0304: Cylinder 4 Misfire Detected

P0113: Intake Air Temperature Circuit High Input

Pending Fault Log

------------------

P0301: Cylinder 1 Misfire Detected

P0304: Cylinder 4 Misfire Detected

Historic Fault Log

------------------

ECU reports no historic faults

Other discovered fault codes

(possibly pending, current or manufacturer specific)

----------------------------------------------------

ECU reports no other fault codes logged

End of report.

 

Things I have done myself to try and see what the issue is.

 

• Changed plugs,
  
• cleaned maf
  
• tried to unplug and drive without maf but no different.
  

Anyone with any idea would be much Appreciated..

 

 

Attached is log file .

trackLog-2012-May-09_20-22-27.csv

Tell us where you live, may be we can send you to a good shop.

Two things I'd do:

1.check the T connector under your TMIC. The vacuum hose is notorious to pop off and throw lots of codes (see here)

2.If this does not help, then you may have to do a compression test before spending anymore dough.

Thanks I will try this whens it light out .

 

I am in Uxbridge.'

avcs stuck.

 

does it idle like shit but run ok over 2500 rpm?

 

the maf and air temp codes can be ignored cause you said you drove with the maf unplugged.

What is " avcs stuck"

 

Uxbridge is about 20 north east of Stouffville.

30-35 min north east of Markham.

Did you have the MAF and IAT codes before or after you unplugged the MAF and drove it? Faulty MAF readings can certainly cause misfires. Misfires don't cause MAF and IAT codes. Is there someone local you can swap a MAF with for testing purposes? Do you have any way of getting the readings from the MAF like an AP, data logger or a scan tool? Also, take a close look at the wiring harness, make sure it's not chaffed, cut, damaged etc.

Thanks

I use torque for my android phone.

I attached the file in the first post.

Yes the maf came up after i unplugged it.

 

it did come up maf code but another came up as I unplugged it.

see codes in first topic

P0102: Mass or Volume Air Flow Circuit Low Input

P0301: Cylinder 1 Misfire Detected

P0304: Cylinder 4 Misfire Detected

 

 

These were active prior to unpluging maf.

My obd2 scan is telling mere there is voltage to the maf

http://en.wikipedia.org/wiki/Active_valve_control_system

 

does the car idle like shit but drive ok over 2500rpm?

Yes it idles bad but under load is fine.

So the answer would be yes over 2500 rpm it smooths out.

i had the same problem. the avcs solenoid valve is sticking. while idling poorly, tap on the solenoid and it should start running ok again.

actualy just realized cyl 1 is the right front cyl and 4 is the left rear. if it was the avcs the misfires would be on the same bank, 1,3 or 2,4

Yes, I've thought of that. It would rule out anything to do with cams, timing belt, valve timing advance etc. The T fitting is ok and the hoses are zip tied to the T but I can't speak for the other end of the hoses...they kinda vanish. If this was a carburated engine I would be looking for a clogged pilot jet based on how it performs, I'm questioning the injectors today. Rough "lopey" idle, revs up and down slightly, casual driving under slight load is jerky but under load or on the throttle it smoothes out and pulls hard. The coil packs on cyls 2 & 4 are new, 1 & 3 appear to be original (orange paint stripe).

Maybe a bit more history will help...I bought this car in June 11 and the engine and turbo blew on my way home from picking it up (23km). Engine was replaced with a used wrecker, turbo replaced with new. The car ran fine on original engine but the replacement had this issue. 2 weeks later the big expensive $1500 cat went and was replaced with new, engine still ran crap. Then another week later this second engine blew and was replaced with another wrecker that ran the same way. Independant garage diagnosed a hole in the big pipe between MAF and...wherever that hose goes $$$. Also replaced the 2 and 4 coils, moto-vac showed nothing "vacuum system is tight" and the "pre-cat" had a hole and was replaced, more $$$. With 1 new strutt I was just under $3000. THEN in early february the turbo went again, just out of warranty. $2100. The problem stayed with the car through engine 2 & 3. Obviously it could be something electrical or that was fitted from 2 to 3, but what? The timing belt was replaced on 2 then swapped to 3 but were done by different shops, how could 2 shops have screwed that up in the same way. Question: Could it be that the loaded ECM from the first (original) engine is incompatible in a small way with engines 2 & 3 of unknown origin? Being cyls 1 & 4 only it seems unlikely but at this point I'd believe it. My frustration is high with this car. I've spent about as much towing and fixing it as I did buying it and it still runs like crap. All trouble aside I really do like the car and would like to have it fixed...within rea$on.

Also notable, the iridium plugs that were in it were a nice tan colour and gapped correctly with a small white build up on the tips, all were the same appearance and none showed any soot or oil deposits. I installed a new set of double platinum plugs gapped to .030 to see if there was a difference...there wasn't. I know iridium are preferred, but why?

I don't know much about data logging...or data itself for that matter but is it normal that my turbo boost is almost always in the negative? The only time it isn't I'd guess I was at or near wot based on the MAF data from the same time frame. Note:this turbo has about 5000km on it and was installed by a reputable, modern shop.

use oem spark plugs because the engine was developed to use them. double platinum plugs were a bad decision my fraaaand. at idle your boost parameter should be negative because this is how an engine works. it's called vacuum.

powered buy roots cyclone technology. never looses vacuum

Everybody says that iridium are the way to go but nobody can say why. I'm starting to think they just like to say iridium. It sounds cool. Anyway, popular opinion says so and that's good enough for me. They weren't available locally to me and I couldn't see going through the trouble of pulling plugs I suspected were bad without having something to replace them with.

I'm aware that at idle the boost should be negative, my question was, is there any reason why it would be reading farther to the negative while accelerating? Maybe a sensor in backwards...grasping at straws but what else have I got? There is boost there for sure...unless this engine makes a whole lot of power without it, and there doesn't seem to be a leak, at least not a significant one as I don't hear a thing and it doesn't run horribly, just a little rough in the idle and that stuttering thing, both of which are annoying and distracting. The turbo is new and I have no reason to suspect anything wrong with it as the car ran exactly the same on the old one.

why? because engineers say why iridium. as you accel the vac should read closer and closer to 0. did you boost leak test it? that will cause a lumpy idle, so will low compression

No I didn't do that test. In my original post there is a data log, though not very comprehensive it shows that at idle my boost is near zero but on the negative side, as I accelerate it gets more negative. Do you know the name or location of the sensor that gives that data? Is this a common malfunction or possibly an error in the data logger? Is this data used to manage a/f or valve/ignition timing etc? This boost number aside, from reading other stories here I'm inclined to suspect front o2 sensor or as you mentioned, compression. As mentioned, this engine came from a wrecker and was said to have 120,000km on it and a car dealer wouldn't lie about that...would they? Then again, engine #2 acted the exact same way. 2 engines with poor compression...could happen, they were scrapped for a reason. 02 sensor was not changed but might have been damaged in the failure of engine #1. To re-cap, engine #1 blew, replaced with wrecker and new turbo and timing belt, ran like shit, then after-turbo cat was replaced still ran like shit, then engine 2 blew and replaced with another wrecker and same turbo same timing belt as it had only 1500km on it. A week later got new intake plumbing and pre-turbo cat and coil packs #2&4...then that nearly new turbo blew and was replaced with a new one. The car has run the same since the first engine went. I'm sure the o2 sensor was common to all 3 engines (I'd remember paying for that). Both engines suffered catastrophic failures, the second was only described as "piston #2 isn't there anymore". to say the people I was dealing with are sketchy would be an understatement so who knows what really happened. My first ever foreign car hasn't been the best experience for sure.

Maybe a wiring harness problem. A shorting circuit in the maf wires, sounds like a nightmare that ended up essentially being a lemon car with the first owner. Follow the maf wire harness all the way and look at it closely for knicks. A fucked up maf sensor reading or wires can lead to the other codes and the rough idling. The maf is extremely important for the ecu to calculate fuel mixture. Also, changing out the injectors wouldnt be a bad idea. Perhaps theyre clogged. A boost leak test is very important and a massive air leak can also cause the symptoms and codes youre seeing. Search google for boost leak testing legacygt.com

your manifold pressure is messed. Im guessing at one point whoever put the new engines in didnt hook something up correctly, like a map sensor. In ambient air, the map reads like -0.15psi at around sea level. Very funky stuff youve got goin on. It seems almost too much for a forum to help you with. If i were you id find a reputable subaru shop to bring it to. And the dealer being the last place. Either you have a gloryhole sized air leak off your manifold or theres some something else

Before starting it read 14, if that's ambient air pressure it's reading it's about right, although I'd have expected it in millibars. After start at idle it's a little over 5 which would indicate vacuum but not much. If there was a large leak I'd think the installers of the turbo would have noticed, if not the first time surely by the third time. 1 pipe was replaced somewhere after the MAF but I don't know which but it was $150 or so if that tells you anything. I thought of injectors and being relatively inexpensive I might just do them, can't hurt.

Question: When the manifold air pressure sensor goes, does it give false or no reading? Having always been a GM guy I have little experience with failing sensors, or engine troubles for that matter. I typically retire them after about 400,000 km and have never blown an engine before.

Thanks for your input btw, I really do appreciate it.