Cylinder misfires or bad injectors, please post here.

Please help. I have P0302 code solid check engine light flashing cruise. Running fine. then i turn off the car and upon starting it wont hold idle just stalls out. If i keep rpms up it runs great smooth and strong. Cleared this once I cleaned the maf and it went away and didnt see it for days. Now its back any idea's. Im leaning toward IACV since it has 118k miles and never had Throttle Body service Just 90K timing and plugs. Also not sure if its related but my OE head unit / AC didnt come on upon start up and wouldnt come back on until i turned car off and back on again. Grounding issue? Edited July 20, 2015 by driving
Addition to problems

Coil pack, plugs, and injector are the first things to check.

 

Start by inspecting the plugs for damage. When have they been changed?

 

Swap Coil pack next and see if the misfire follows to the cylinder you swap to. Then swap injectors to see if it follows. If the code follows during a swap, replace that coil pack/injector.

 

A bad ground will cause any number of issues. They may or may not be related. At least you have some place to start. Check all engine harness connectors as well. Lok for the bonding wire that goes between the engine and the chassis as they have a tendency to break down over time.

what he said.

 

if coil, plug, or injector won't fix the issue, then time for leakdown/compression test..

I'd check the intake manifold and/or TGV gaskets for leaks too...before doing a compression or leak-down check.

Yeah the manifold was off a year ago for fuel lines. And had a bank 2 lean code six months ago. Hmmm

My independent mechanic is at wits end (last attempt was free) - - all spark plugs have been replaced, coils have been replaced, and the injectors have been all pulled cleaned and tested. Compressions tests are well within the acceptable range as are all vacuum tests and the only “straw to grasp” is the valves may need to be adjusted but he does not have the Subaru tool to do it. The 2009 Legacy GT only has 130,000 miles on it. Earlier, the dealership did not know if a valve job for $3k would solve the problem, but they would take the car as a trade-in and the mechanic wanted to buy it (outside the dealership). I love the car and feel an attachment, but why would I want to trade-in for a Subaru?? I have just gone into the routine of disconnecting the battery for 15 minutes to re-set the engine light for 10 minutes and drive to destination. The dashboard continues to be “sticky”, an other non-Subaru problem so many other’s have listed. My husband’s 05 and then 14 Honda’s (the 05 had 310K miles with less that $500 in total repairs including a cruise control switch) have never treated him so badly. Now when I see a Subaru ad on the TV all that comes to mind the McDonald’s ad of “I’m loving it” - - the screwing!!

What is the code for the misfire?

When does the misfire occur? cold idle? warm idle? any idle? or at any rpm ranges?

Did they check the valve clearance? fyi, my 05 has 70k and clearance was already too tight on a valve.

Changed #2 injector. Idles much smoother. Hope that the cel does not return. Fingers crossed.

I have an 06 LGT spec.B w/ misfire issues. Here are the key notes from the mechanic that did the diag, I'm sure it will make more sense than if I tried to explain it myself.

"Choppy on Aggressive Acceleration w/Major Loss of Power
- Aggressive Acceleration Cause ''In Progress'' Cylinder Misfire
- Roughness Across All 4 Cylinders Starting with 2 and 4
- Knock Sum - Between 8-16 Counts
- Idle AFR - Somewhat Rich - 14.1-14.3
Cylinder Compression Test - Warm/Dry:
Cyl 1 - 151.0psi
Cyl 2 - 140.5psi
Cyl 3 - 146.0psi
Cyl 4 - 145.0psi
Results Healthy and Within Specification
Notes - Post-Work:
- Fuel Pressure Within Specification
- Compression Test - Healthy
- Coil Packs Frayed
- MAF Sensor - Did NOT Appear to be Damaged - No Change in AFR after Swapping or Cleaning
- Cylinder Roughness First Counted in Cylinder 2 and 4
- CEL - Misfire All Cylinder 1 and 2 with 000 codes for 3 and 4". "“OCV Diagnostic Notes:
- OCV on both left and right intake appear to be delayed in response and a decrease in output (angle %) is also apparent. This could possibly indicate a failure in the OCV (solenoid), the cam sprockets or the oil delivery itself (clogged oil line/foreign material). - Recommend Installing new OCV (x2) and Inspection/Clean during install."

 

Basically, the car drives fine at low speeds and low rpm's but under load misfires. The boost leak at the turbo inlet that was mentioned above has been fixed but the OCV's haven't been replaced. The shop that I brought it to is pretty certain the catalytic converter is blocked up and that's what's causing the misfire's. I found a catalytic converter for sale that came off a 05 lgt, is there any reason to suspect that it wouldn't bolt onto my 06?

Intake and/or TGV gaskets?

well first time post

 

I think I just ruined my car

 

Went to high in the rpms

 

And now check engine light flashing and car is shaking like crazy

What is the CEL code?

 

Did you mis-shift and overrev or did you hit the rev limiter before shifting?

well first time post

 

I think I just ruined my car

 

Went to high in the rpms

 

And now check engine light flashing and car is shaking like crazy

Hope it turns out OK. On the bright side you nearly have a haiku.

 

Sounds like you may have done this on a downshift. Rev limiter should protect you the other way.

Codes where Po171

To lean and

Misfire on 123

Not random

misfires

 

I was going from 2nd to third

went to about 6k right before the rev limiter kicks in And after that shift I noticed it stop at the next stop sign and

 

no power could barely get out of the intersection and then parked it right away

 

 

 

its at 100k

has a new timing belt water pump and clutch

 

 

I got the car at 97k and it ran great still I got that lean code

 

 

 

 

What think it is

ignition pack

Or the timing is off

 

It smells really rich when you start it

 

And it all started with that Po1717 code

 

 

 

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Found out it was a bent spark plug has anyone else had this??

 

 

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Boost leak test it...

 

Codes where Po171

To lean and

Misfire on 123

Not random

misfires

 

I was going from 2nd to third

went to about 6k right before the rev limiter kicks in And after that shift I noticed it stop at the next stop sign and

 

no power could barely get out of the intersection and then parked it right away

 

 

 

its at 100k

has a new timing belt water pump and clutch

 

 

I got the car at 97k and it ran great still I got that lean code

 

 

 

 

What think it is

ignition pack

Or the timing is off

 

It smells really rich when you start it

 

And it all started with that Po1717 code

 

 

 

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So I know I'm here that there is a small knock in the engine witch he says he causing the spark plugs to bend

 

He said he put a scope in the engine but could sill not see what was wrong

 

 

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Do you have the right spark plugs for your car?

Yea I have the right plugs

 

 

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Post a pic of the bent plug. That should not be happening unless the plug is somehow sitting deeper in its pocket.

 

I would pull it and from another cylinder and compare the exposed depths. Something weird is going on. Either that or something really bad.

Looks like I get to join this club.

 

Bought my 2006 Legacy GT in December of 2012; the previous owner had just replaced the engine and it had maybe 10,000kms on it when I got it. Since then, I've put about 40,000 more kms on it. Slowly been upgrading components (nothing internal, though), and it's now at Stage 2. Installed Killer B equal length headers a couple of months ago, and have had sporadic P2096 (Post Catalyst Fuel Trim System Too Lean) CELs since installing the headers (which seems par for the course, so I wasn't worried).

 

Then the wife takes the car for a business trip and of course about halfway there the car starts throwing CELs left, right, and center. I had her pull the codes on the AccessPort and they were P0303, PFFFE, PFFFF, and another P2096. I had her reset the codes, and immediately after that, the car started stalling. It's now sitting at a dealership, so I'm waiting to hear their diagnosis.

 

I'm hoping it's something simple like the injectors, coilpack, O2 sensor, or MAP and not burnt valves (which seems unlikely given that it's cylinder 3 misfiring instead of the usual cylinder 4).

 

Maybe the P2096 codes prior to this were actually pointing to the front O2 sensor on its way out?

 

Update: thankfully, a simple fix. Dealership moved the injector to another cylinder and the misfire followed. Should have it fixed by the end of the week.

 

Also gives me an excuse to upgrade the injectors (not right away, but soon).

 

Quoting myself for an update.

 

Had a few trouble-free months, other than back in July when the car had a weird issue where it seemed to lack power when cold and going uphill. I cleaned the throttle body and MAF and that seemed to fix that issue.

 

After that, it would throw the very occasional misfire code (usually cylinder 4). At least some of these I attributed to having installed a lightweight crankshaft pulley.

 

Then just this week, driving on the highway, I noticed a pretty severe lack of power when going uphills/passing and it threw a flashing CEL. When I arrived in town, I reset the ECU (it was a cylinder 4 misfire code again), and immediately after that it had problems holding idle and kept stalling. At that point, I brought it in to a shop with the ECU showing a cylinder 4 and cylinder 2 misfire. They diagnosed it as a burnt exhaust valve on cylinder 4.

 

So now I'm getting the car towed back home (100 miles) for a top-end rebuild. Anything else I should do while it's apart? I was thinking of going with ARP studs for the head and maybe an upgraded head gasket.

There is a mixed school of thought on ARP studs. I think the OEM bolts are fine for use and one forum member was running them on a 580hp build if I recall correctly. You can't go wrong with ARP, but the stock bolts are reusable and on a mild or stock build, I see no reason to spend the extra money. The OEM gasket is fine unless you need a thicker one to account for machining of the head.

 

Please (and this goes for everyone else) remember that if you have a CEL, especially flashing one, don't reset the ECU until the problem is resolved. The ECU doesn't just throw codes for the fun of it. Resetting won't solve your problem and you lose valuable troubleshooting information.

There is a mixed school of thought on ARP studs. I think the OEM bolts are fine for use and one forum member was running them on a 580hp build if I recall correctly. You can't go wrong with ARP, but the stock bolts are reusable and on a mild or stock build, I see no reason to spend the extra money. The OEM gasket is fine unless you need a thicker one to account for machining of the head.

 

Please (and this goes for everyone else) remember that if you have a CEL, especially flashing one, don't reset the ECU until the problem is resolved. The ECU doesn't just throw codes for the fun of it. Resetting won't solve your problem and you lose valuable troubleshooting information.

 

Good to know, thanks.

 

My take on reading this is that there's basically nothing to be done (top-end wise) in the way of either enhancing reliability or preventive maintenance other than the obvious of doing the timing belt and water pump at the same time? Higher-flow injectors have been on my wishlist for awhile, but I can still do those myself at any point anyway.

 

Regarding resetting the CEL, this all happened *very* quickly. I threw the initial CEL on the highway about 50-75 kms before I reset. I looked at the codes, cleared them, and things went quickly downhill immediately after that.

 

I've been looking for any possible signs or symptoms previous to this point, and even in hindsight I don't see anything that was giving me advance warning of this failure - except perhaps for a single cylinder 4 misfire code a couple of months ago, which by itself doesn't really tell you much - especially when running a lightweight crank pulley, which is known to throw spurious misfire codes.

Edited December 21, 2015 by Arcteryx

I wasn't able to sense any problems when mine cooked exhaust valves in cyl 2 & 4, but the mechanic could tell. I guess because the change was so gradual I didn't notice.

 

What else to do while in there? Christ, what isn't there to do. Want a copy of the Saunders invoice from my adventure?

 

I did the clutch and catless up-pipe, new belts, various hoses, starter. Basically the bits that are hard to get to and wear out quickly. In hindsight I should have done the intake tube too.

I had a bad misfire and couldn't rev high once. I found it to be a cracked spark plug. Sometimes the problem is a simple fix!