Lean with Missfire's

[Alin]

I almost think its an injector issue. The car will idle perfectly fine at times and then it just bumps up to 20 on the AFR. I feel like the car shouldn't have a miss with the lean code I'm still getting in the car. Maybe timing? I just some highway pulls while data logging, just need someone to look it over now.

First of all, do NOT ever accelerate more than 50% throttle until your car is resolved.

Second, it seems like you live close to @Eagleye, so maybe you guys should communicate and check if you can meet up in person so he can help you out. It's one thing to try and help online, and a completely different story in the flesh.

Third, get us at least one good picture of the engine bay.

Fourth, Are you sure the BPV (bypass valve) and EBCS (electronic boost control solenoid) are stock? (This is why I'm asking for pictures.)

Check the following parameters:

-Cylinder 1 Roughness
-Cylinder 2 Roughness
-Cylinder 3 Roughness
-Cylinder 4 Roughness

Could be a number of things, but first you need to determine which cylinder, coil pack, spark plug, or injector is acting up.


This is an organized footnote/list of the modifications that we are aware of:

-K&N Typhoon intake
-Invidia downpipe
-HKS catback exhaust
-Cobb Accessport
-partial Cobb intake?
-Cobb OTS Stage 2 91/LWG map

 

[Mason Johnson]

[MENTION=1172]Alin[/MENTION] I know at the moment all 4 cylinders are missing. Where do I find those parameters?

 

[Alin]

@Alin I know at the moment all 4 cylinders are missing. Where do I find those parameters?

Check my previous post for updated content.

It would be under the Monitor selection screen of the Cobb AP. "Cylinder 1 Roughness."

 

[Eagleye]

Sorry, busy day yesterday. If you can, upload any data logging to google drive and share the links here. That method works pretty well. [MENTION=1172]Alin[/MENTION] has you pointed in the right direction. I'd like to agree with you on the injectors but not if all 4 cylinders are missing. That sounds like it could be anything from issues with you aftermarket downpipe (leaks, clogged cat if it is catted, bad o2 sensor), fuel pump or regulator issues, spark plug issues, or some combination. Given that a reflash helped but didn't solve the problems, I do not think it is a tune or computer related problem. In an attempt to save the motor the computer was/is making compensations that prevent lean conditions which is making it pig rich at idle and cruising speeds causing other problems.

First thing I would do from here if I were you, swap in the Cobb intake (which filter you use will make little impact). Check for any boost and exhaust leaks. If you have the means, tools, know how at this time, I would at the very least pull a spark plug to see what condition they are in and consider replacing them given the mileage and lack of maintence history you have for the car. Reflash with the new intake (and spark plugs if necessary) in place. Log normal driving and a couple of low boost pulls. Save the files to your computer as a spreadsheet and upload them to google drive. Share the links in this thread and we can take a look. I/others here will not BS you on any of this, if I/others do not see anything obvious we will defer to Holy or another known tuner on this forum to get their input.

 

[Mason Johnson]

Thanks for the help! I'll see what I can do this weekend when I have the time. Picture of my engine bay as requested:

 

[Alin]

Alright, so a few things:

-You have some bolts missing in some places.
-You don't have a belt on the A/C compressor so it's evident your A/C doesn't work. Can you confirm?
-What is the zip-tie that's directly next to the BPV holding?
-That (either oil or coolant) feed line definitely looks out of place. It must be aftermarket. I'm assuming it connects to the turbo.
-I cannot determine whether you have a stock EBCS or an aftermarket one. You would have to remove the plating and take a picture so we know for certain. (It's that black metal piece directly above the air filter. I believe 3 bolts hold it in place.)
-What's the capped off wiring by the turbo/coolant overflow tank? Did the car come with an aftermarket sub-woofer or something?

Another thing I'd recommend is that you remove the black piping from the 3 connection points and check what it looks like inside. More often than not, some nasty sludge gets built up in there. If there is any present, you can either blow the air out (whatever means you choose to do so with) or you can swing the pipe in a momentous way that forces the sludge out. (I've done it in my backyard in the past.)


One more thing, can you also get us a close up shot of the turbo?

 

[Mason Johnson]

Steal lines goes to the turbo. Assuming its an oil feed or return line. The lines coming off the turbo are steal braided lines. The wires that are just sitting there capped off went to an aftermarket light bar that I took off. Its hard wired to a button inside the car. A/c doesn't work currently not to worried about it. The zip-ties are holding hoses to the BPV which obviously needs to be taken off and replaced with normal hose clamps (Just noticed these yesterday.) I'll get the picture of the EBCS later today. Its the black plate by the cut off wires correct?

 

[Alin]

Steal lines goes to the turbo. Assuming its an oil feed or return line. The lines coming off the turbo are steal braided lines. The wires that are just sitting there capped off went to an aftermarket light bar that I took off. Its hard wired to a button inside the car. A/c doesn't work currently not to worried about it. The zip-ties are holding hoses to the BPV which obviously needs to be taken off and replaced with normal hose clamps (Just noticed these yesterday.) I'll get the picture of the EBCS later today. Its the black plate by the cut off wires correct?

Yes, that is correct. In your picture, you can see the connector that plugs into it, which is blue.

 

[Mason Johnson]

Okay update time. I have been busy for the past couple of weeks. I've replaced the intake with the cobb sf intake. I've also replaced the spark plugs. While doing the spark plugs I also did the valve cover on the passenger side of the car due to it leaking oil. Car still misfires, but now its worse. The car has no power and barely drive. I've re-tuned and reset my ECU and problem still persists. I'm thinking it maybe one of the coil packs being bad. Any recommendations?

 

[Eagleye]

If you are still experiencing issues on all 4 cylinders I doubt it is a coil pack issue. I would be considering the possibility of a bad fuel pump/clogged fuel filter or bad fuel pressure regulator. If it is an issue at only 1 or 2 cylinders I would swap coil packs/fuel injectors to see if the problem moves.

 

[Alin]

How many miles total on the chassis? If over 100,000, I'd recommend you replace the entire fuel sending unit with sock filter completely for peace of mind going forward (to add to what [MENTION=692]Eagleye[/MENTION] said).

 

[Mason Johnson]

Sorry it's been taken me so long to reply. The car has 245k miles on the car. I've replaced all the spark plugs with NGK iridium and replaced all the coil packs. I'm now down to 2 CEL's. 1 for cylinder 1 misfire and EGT sensor code which I just found out today how to fix. Car has had a better fuel trim since all of the recent repairs. I'm usually sitting around 15-20 on idle still but it idles closer to 15 now with a creep up to 20-25 after letting off throttle. I feel as the EGT is what might be causing the cylinder 1 misfire but maybe not? Anytime I've reset the ECU the cylinder 1 misfire always shows up. The engine itself is very clean and looks to be in good condition after looking at the valve cover when I changed the gasket. Didn't see any metal in the oil and the head gasket is still good.

 

[Batmobile_Engage]

I wish I knew more about the EGT code and where the reading is coming from (where the sensor is). But just spitballing here, I would assume the EGT code tripped because the sensor reading is too hot. Too hot usually means a lean AFR (and probably relates to the periodic misfire), which of course could cause detonation.

If you're only having a problem on 1 cylinder, I would try to log and see if fueling seems to be different from that 1 cylinder versus the other ones. If you haven't replaced the fuel filter and sock strainer, I would still do that. But I wonder if you have a poorly flowing fuel injector at cylinder #1. If you can, maybe think about replacing injectors or having them flow tested/refurbished.

In the meantime, you could always move that injector to a different cylinder and see if the problem moves to that cylinder. Of course that is kind of a lot of work just for troubleshooting purposes and if you had any damage to cylinder 1 because of it, I'd hate to have you spread around the damage.

Just trying to offer some options...

 

[Mason Johnson]

EGT is positioned in the up pipe and what I've read online when they go out most people just but a resistor in the plug to get rid of the code and not worry about it along with removing the sensor and blocking the hole. I would go through and check the injectors but I'm not that mechanically incline to do such work. Guess it needs to go to a shop/subaru.

 

[Batmobile_Engage]

EGT is positioned in the up pipe and what I've read online when they go out most people just but a resistor in the plug to get rid of the code and not worry about it along with removing the sensor and blocking the hole. I would go through and check the injectors but I'm not that mechanically incline to do such work. Guess it needs to go to a shop/subaru.

Found on another site, and in reference to the 2002 WRX (so it probably isn't any different for you):

"The stock EGT sensor ONLY is there to monitor the condition of the pre-turbo catalytic converter. It has no function for tuning the car's ignition or fueling.

However, if it detects that the third cat has overheated (and is in danger of crumbling and/or catching on fire), the ECU may very well put the car into "limp mode" which would essentially eliminate any good power and boost.

If you have eliminated the pre-turbo cat (with an aftermarket uppipe), then you have no reason to keep this sensor in place so doing the 2.2kohm resistor mod + 12x1.25mm bolt makes great sense. You'll never get an EGT-probe-related CEL from the resistor and the bolt in place of the probe will offer less flow restriction in the uppipe since the bolt won't actually protrude into the uppipe like the probe does."

 

[Batmobile_Engage]

Originally, I was confused about the EGT code because I *thought* you said the code pertained only to cylinder #1 . But I guess the misfire code was only cylinder #1 and the EGT code was from the up pipe sensor.

Does this seem correct?

 

[Mason Johnson]

Yes that is correct. Have no idea what is causing cylinder 1 misfire. EGT code showed up for the first time today.

 

[Batmobile_Engage]

Well, in some ways I would kind of ignore the EGT code for now, assuming it is a symptom of a lean afr in cylinder #1. So then, back to what I said about that injector (and possibly a fuel filter+sock replacement just to be safe, if it's old)...

I know it can seem to be a very complicated task, but it's really not too bad if you are handy, label everything with masking tape and take lots of pictures. It looks worse than it is. Let me know if you plan to try it. I can give you a list of stuff you'll need.

 

[Alin]

@Mason Johnson , also run a fuel injector cleaner as soon as you can. It's cheap and you can rule another thing out. Also, it can only improve things. Another option that's a bit more extensive is seafoaming. Injector cleaner is super easy and simple to do, though.

 

[Mason Johnson]

Update: A lot has been done since my last post. But still no fix. Honestly seems worse than before. I replaced all the coolant lines/vacuum lines and as well as all the inter-cooler hose's. New intake gaskets new turbo inlet. I'm on the cobb SF intake, no longer the AEM. Car still persists to have issues. My mechanic that I've been taking the car to is telling me the misfires that I'm getting are coming from cylinders 1 and 4. All spark plugs have been replaced along with coils. I even tried replacing the new coils on cylinders 1 and 4 with another new set, nothing worked. This is were I am as far as what is happening and the issues it's having. Rough idle when up to temp. Car will idle normal upon cold start till about when the engine reaches around 130-150 in coolant temp I start to feel the miss and the car drops in idle to around 500-600 rpms. When revving the car upwords to 4k the car likes to stumble a little around the 2800-3500 rpm range. When letting off the throttle the rpms will fall as low as 350-400 rpm range almost stalling out. My new guess is going tword the fuel system. Nothing has been replaced so far in the fuel side. I'm thinking about replacing the fuel filter now which I probably should have started with. If anyone has any ideas feel free to toss them.