P0171...again

[Carmania24]

Hello All,

 

N00B here,

 

I got a new/used engine installed just over a month ago at a shop. Now I had the CEL come on again, but not for misfire but for P0171. I am not sure what is causing it. It does not idle rough, it starts right up and no overheating. I am thinking it could be my fuel pump? Car has 175,000 miles on it. But the fuel has been good, never has given me a problem before.

 

Also, when I drive it hard (like shifting right before redline) smoke starts coming out of the engine, not a lot or clouds of it but just enough and it smells bad. I opened the hood before and it looked like it was coming out of the turbo area but I could not tell (Im a bad mechanic). However driving normally, theres no smoke whatsoever.

 

Thanks.

[Notorious]

MAF could need cleaning. The fuel pump after 175k could be due for a replacement but you’d have other issues on top if it was failing. Check for intake vacuum or boost leaks, especially look for the Blue t-fitting under the intercooler, you’ll need to pull it off to get to it.

 

As for the smoke, it’s coming from the engine bay not the exhaust in the back right? If the smoke is blue that is definitely oil leaking somewhere so look for oil dripping onto the exhaust. Any oil consumption issues? I’d take it back to the shop for them to fix it because it might be their fault from the engine install.

[Carmania24]

MAF could need cleaning. The fuel pump after 175k could be due for a replacement but you’d have other issues on top if it was failing. Check for intake vacuum or boost leaks, especially look for the Blue t-fitting under the intercooler, you’ll need to pull it off to get to it.

 

As for the smoke, it’s coming from the engine bay not the exhaust in the back right? If the smoke is blue that is definitely oil leaking somewhere so look for oil dripping onto the exhaust. Any oil consumption issues? I’d take it back to the shop for them to fix it because it might be their fault from the engine install.

 

I shall clean off the MAF, the first time I got the car diagnosed he replaced the MAF, so that is weird. I was thinking the 02 sensor can be bad as well, not sure when/if it was replaced. I did have an issue with the boot leading to the turbo (https://www.ebay.com/itm/NEW-2005-2006-Subaru-DUCT-ASSEMBLY-AIR-INTAKE-OEM-legacy-Outback-14459AA340/201922613992?epid=1741151454&hash=item2f038692e8:g:sN4AAOSwY3BZFh8A:rk:6:pf:0)

Me and my buddy just jerry rigged on a piece and seems to be working fine. We did remove a lot of hoses and the intercooler so maybe over time it became lose. We did this process over a month ago though.

 

As for the smoke, it is white- not blue. I checked the coolant and oil 2 days ago and it is not burning; oil is still good. No smoke from exhaust. If the exhaust manifold is leaking, could that cause smoke to come from the engine?

 

Thanks!!

[Notorious]

I shall clean off the MAF, the first time I got the car diagnosed he replaced the MAF, so that is weird. I was thinking the 02 sensor can be bad as well, not sure when/if it was replaced. I did have an issue with the boot leading to the turbo (https://www.ebay.com/itm/NEW-2005-2006-Subaru-DUCT-ASSEMBLY-AIR-INTAKE-OEM-legacy-Outback-14459AA340/201922613992?epid=1741151454&hash=item2f038692e8:g:sN4AAOSwY3BZFh8A:rk:6:pf:0)

Me and my buddy just jerry rigged on a piece and seems to be working fine. We did remove a lot of hoses and the intercooler so maybe over time it became lose. We did this process over a month ago though.

 

As for the smoke, it is white- not blue. I checked the coolant and oil 2 days ago and it is not burning; oil is still good. No smoke from exhaust. If the exhaust manifold is leaking, could that cause smoke to come from the engine?

 

Thanks!!

 

Definitely check all those intake lines, that jerry rigging could be the cause. The only way a leaking exhaust manifold would cause the smoke is if the hot gasses are burning something around it. Coolant steam I heard smells kind of sweet and you described it as smelling bad so it could be something else. I wouldn’t recommend trying to confirm the smell since of it is coolant it would be toxic.

 

Hard to say where it’s coming from until you get under there and see the source of the smoke or steam. It could be water from the AC dripping on the exhaust but I doubt it. Try to jack the car up while it’s been smoking or see if revving the car in neutral will cause smoke.

[Carmania24]

Definitely check all those intake lines, that jerry rigging could be the cause. The only way a leaking exhaust manifold would cause the smoke is if the hot gasses are burning something around it. Coolant steam I heard smells kind of sweet and you described it as smelling bad so it could be something else. I wouldn’t recommend trying to confirm the smell since of it is coolant it would be toxic.

 

Hard to say where it’s coming from until you get under there and see the source of the smoke or steam. It could be water from the AC dripping on the exhaust but I doubt it. Try to jack the car up while it’s been smoking or see if revving the car in neutral will cause smoke.

 

Thank you for the prompt response. The heater core is leaking, so I think it maybe just hitting the turbo thus creating the smoke.

 

And I will, but the engine does not seem to be misfiring or have a lack of power. I will also save up for a new fuel filter. I will clean the MAF as well. I am seeing my buddy tomorrow as we are replacing control arm bushings.

[apexi]

In your shoes I'd have a shop do a smoke test for a disconnected vacuum hose, bad intake manifold gasket, cracked vacuum hose, torn somethin after the maf sensor.. I'm guessing extra air is getting in somewhere, but no enough to cause a misfire.

[apexi]

By the way, did you ever get this sorted out with the leaking intake tube? I think that would certainly allow extra air to get into the engine after the maf sensor, throwing the p0171 lean code.

 

https://legacygt.com/forums/showthread.php/help-part-276557p2.html

[Carmania24]

In your shoes I'd have a shop do a smoke test for a disconnected vacuum hose, bad intake manifold gasket, cracked vacuum hose, torn somethin after the maf sensor.. I'm guessing extra air is getting in somewhere, but no enough to cause a misfire.

 

I will have to do that, or just spray it all around with my buddy tomorrow since we will be doing some maintenance stuff.

 

By the way, did you ever get this sorted out with the leaking intake tube? I think that would certainly allow extra air to get into the engine after the maf sensor, throwing the p0171 lean code.

 

https://legacygt.com/forums/showthread.php/help-part-276557p2.html

 

The intake boot to the turbo was ripped. Replaced it with a silicon jerry rig, was fine. No CEL after doing it, not till now atleast.

[Carmania24]

—UPDATE— Oil and coolant levels good. Power steering leaking, could be burning?

[Carmania24]

—UPDATE 2— Heater core leaking, so I think that is hitting something thus burning and causing the smoke?

[Carmania24]

--UPDATE 3--

It is NOT the heater core causing this. Found out the smoke appears to be coming from the intake manifold (bottom of the engine right behind radiator). My buddies suspicion of a leaky power steering is correct thus causing the white smoke- not a lot except this morning, and having white smoke with faint smell. The car does not drive or idle weird, though I think it is time to do the pump or atleast try to stop it from leaking a lot. Kind of weird because the reservoir seems to be full still. Any ideas? Will edit this post and add in a picture later on.

 

Thanks.

[Notorious]

Replace the little O-ring gasket on the top of the power steering pump. There’s a walkthrough thread on here; just search for it. It could be leaking just enough now that the weather is getting colder. It’s only like $5 from a Subaru dealership, it should be orange not black. It makes sense that it leaks more after driving longer or rougher since the RPMs are pushing the pump more. The power steering leak likes to accumulate right on top of the block and can leak onto the exhaust manifold or up-pipe.

 

Also inspect the plastic tube that keeps the gasket in, mine ended up being cracked from over tightening and I had to JB weld it together. The gasket has to be set in just right or else you’ll rip it. I bought two at the dealership just incase and I’m glad I did.

[Carmania24]

Replace the little O-ring gasket on the top of the power steering pump. There’s a walkthrough thread on here; just search for it. It could be leaking just enough now that the weather is getting colder. It’s only like $5 from a Subaru dealership, it should be orange not black. It makes sense that it leaks more after driving longer or rougher since the RPMs are pushing the pump more.

 

Also inspect the plastic tube that keeps the gasket in, mine ended up being cracked from over tightening and I had to JB weld it together. The gasket has to be set in just right or else you’ll rip it. I bought two at the dealership just incase and I’m glad I did.

 

Thanks for the prompt response. I will go out and buy the ring, hopefully the dealer here has it. $5 for a gasket seems ridiculous, but if it can save my pump then I will be happy. It does not really whine, only when I am fully locking the wheel then it will at times. But most of the time I do not really fully lock it. Steering is not hard at all. I will also wipe everything down and maybe even buy a stop leak and at it in. Looks like the fluid is just about to reach HOT MIN. Hopefully this ring will do justice. I also see you're in cali-- are you in NorCal or SoCal?

[Notorious]

Thanks for the prompt response. I will go out and buy the ring, hopefully the dealer here has it. $5 for a gasket seems ridiculous, but if it can save my pump then I will be happy. It does not really whine, only when I am fully locking the wheel then it will at times. But most of the time I do not really fully lock it. Steering is not hard at all. I will also wipe everything down and maybe even buy a stop leak and at it in. Looks like the fluid is just about to reach HOT MIN. Hopefully this ring will do justice. I also see you're in cali-- are you in NorCal or SoCal?

 

The hose clamps around the hoses and hardlines coming in and out of the power steering pump should be inspected too. Whine at full lock isn’t normal after the car has warmed up and even when cold then it means there’s a little air in the system.

 

The power steering will naturally bleed itself while driving but if it is leaking, then air is constantly also getting in. I also used a bottle of Lucas power steering stop leak but not sure if it was recommended in systems that use ATF fluid in the power steering like ours instead of traditional power steering fluid. No problems thus far though after 10k miles and the JB weld is holding tight.

[Carmania24]

From the eye, looks like the hoses and clamps are on pretty tight. I will double check but I am confident it does not whine a lot. I do believe your suspicion that the O-ring is bad; it looks like fluid comes out from right there. But there is fluid literally almost all over the PS, so it is a little hard to tell. Thanks again.

 

part number: 34439FG000

[Carmania24]

Sorry for double post-- o-ring is black. Does that mean it is bad? Also is it supposed to be attached to the plastic piece or the power steering pump?

 

I know have the whining noise like this guy plus bubbles:

 

My subaru is out of stock. Going to o'reilly right now.

 

Welp oreilly didn’t help. And the noise went away after tipping off the fluid. After further inspection I give up. I can’t tell anymore if PS pump or heater core.

[Notorious]

The black O ring is the old material and the orange is the newer stuff. You have to make sure it sits right inside the pump. Can’t remember it if wraps around the plastic piece or not after you put it back together but I did not wrap it around it before as far as I remember.

 

Bubbles means there is air in the system. After replacing the O-ring, it should bleed itself over time. Just go lock to lock a few times, wipe everything down, and go for a drive. If you have no leaks at this point the whine should be pretty much gone and there shouldn’t be any new fluid around the pump

[Carmania24]

The black O ring is the old material and the orange is the newer stuff. You have to make sure it sits right inside the pump. Can’t remember it if wraps around the plastic piece or not after you put it back together but I did not wrap it around it before as far as I remember.

 

Okay I will have them order it. Thank you very much! No whine after filling it. So I can rule out the pump being the main thing for the smoke. But will still replacing o-ring

[relative4]

Bad O-ring leaks air IN and causes whining. Oil leaking OUT is caused by a cracked hose. Once you pull it, you'll find radial cracks currently hidden by the pump fitting.

[Carmania24]

Bad O-ring leaks air IN and causes whining. Oil leaking OUT is caused by a cracked hose. Once you pull it, you'll find radial cracks currently hidden by the pump fitting.

 

It is odd, because the fluid in the reservoir seems to be ok and stable. No loss in fluid. Same goes with Oil and Coolant. I am uploading a video to youtube to show the smoke. Will post a link once uploaded. Thanks everyone!!

[Carmania24]

Videos showing my issue:

[relative4]

Your right valve cover gasket is leaking.

[Notorious]

Hard to tell but it could also be one of your cam seals if it is dripping out of the timing belt cover onto the headers. I had a minor valve cover gasket leak for months and it never smoked or dropped on the up pipe, of course the severity of your leak could be different.

 

Do a good degreasing of the valve covers and the timing belt, let everything dry, and drive the car again to confirm the source.

[Carmania24]

Your right valve cover gasket is leaking.

 

Dumb questions- wouldn't there be a smell and/or a misfire? How bad would it be if I did not get it replaced for a while?

 

Hard to tell but it could also be one of your cam seals if it is dripping out of the timing belt cover onto the headers. I had a minor valve cover gasket leak for months and it never smoked or dropped on the up pipe, of course the severity of your leak could be different.

 

Do a good degreasing of the valve covers and the timing belt, let everything dry, and drive the car again to confirm the source.

 

I hope not, I just got a newer used engine just over a month ago.

 

Thank you both

[Carmania24]

—bump—