Rich idle and -25 correction

[_Broken_WRX_]

My car had been having an issue with dying whenever I slow down to a stop and push in the clutch. Today it died and I went to start it back up and it usually starts right back up with no issues, but today it started up but my idle was pegged at 11.1 (as low as my ap can read) and my afr correction 1 was pegged at -25. The car was nearly impossible to drive and died three more times on the way home. I was hoping it was just bad gas so I limped it to a station but this had little to no effect on the issue. Any ideas on this one? I was thinking vacuum leak but that would make it lean out and add fuel correct?
Thanks


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[Alin]

[MENTION=1]IGOTASTi[/MENTION] [MENTION=9]HolyCrapItsFast[/MENTION] [MENTION=662]Batmobile_Engage[/MENTION] [MENTION=652]Grinder34[/MENTION] [MENTION=5388]Raven32[/MENTION] [MENTION=1868]Boogieman98[/MENTION] [MENTION=692]Eagleye[/MENTION]

 

[Eagleye]

Any engine codes or smoke? My initial thoughts would be looking for leaks post MAF and questioning the condition of the o2 sensors.

 

[_Broken_WRX_]

Any engine codes or smoke? My initial thoughts would be looking for leaks post MAF and questioning the condition of the o2 sensors.

The car has been throwing codes for the rear O2 for a couple months now because I dont have the harness to the rear sensor. But since this issue just happened im not sure that its related. No smoke though besides a little oil on startup.


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[Boogieman98]

I had something similar like this happening before. I had an exhaust leak in the flex portion of my uppipe(Grimspeed warrantied it) and a intake leak in the coupler from intercooler to intake. Now which one caused the issue I'm not sure but did almost exactly what your describing. Oh and this was on engine number three right after install


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[_Broken_WRX_]

I had something similar like this happening before. I had an exhaust leak in the flex portion of my uppipe(Grimspeed warrantied it) and a intake leak in the coupler from intercooler to intake. Now which one caused the issue I'm not sure but did almost exactly what your describing. Oh and this was on engine number three right after install


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My intercooler was pulled a month or so to swap my transmission and it hasnt made full boost since then. Im thinking there is just a huge leak somewhere but I cant seem to find it.


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[Eagleye]

The car has been throwing codes for the rear O2 for a couple months now because I dont have the harness to the rear sensor. But since this issue just happened im not sure that its related. No smoke though besides a little oil on startup.


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Yeah when this came up before I thought we came to the conclusion that you needed to disable the rear o2. Does the problem persist if you reset the ECU? Whether it is linked to this problem or not, you should address this issue by fixing it or disabling it. If you continue to run the car in that rich of a condition you could kill the cat and cause other internal engine damage.

It will be difficult to further diagnose this issue until the o2 sensor is taken care of. Look for others to chime in though as they may have had different experiences.

 

[_Broken_WRX_]

Ive tried clearing the code and it doesent really seem to do anything. Im having a hard time finding the right part for the rear O2 I tried to make a harness for it and its getting signal from the rear sensor but its still throwing the code for some reason. Subaru is supposed to have the part I need back in stock by may though so I will get it as soon as I can.


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[_Broken_WRX_]

Im going to clean my MAF today but Im not sure what that will really do for me.


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[Eagleye]

Ive tried clearing the code and it doesent really seem to do anything. Im having a hard time finding the right part for the rear O2 I tried to make a harness for it and its getting signal from the rear sensor but its still throwing the code for some reason. Subaru is supposed to have the part I need back in stock by may though so I will get it as soon as I can.

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Clearing the code is not what I mean. Clearing the code just means you don't have a code but does nothing to the car or any systems. You need to do an ECU reset to reset the fuel trim learning. And disabling the rear o2 input would also require different steps than just clearing the code. If the AFR looks good after a reset I would think this problem is mainly coming from that o2 sensor. Even if you choose not to reset the ECU now, I would be doing it after installing the new harness so the computer is starting fresh and making adjustments from a good starting point.

 

[Eagleye]

Im going to clean my MAF today but Im not sure what that will really do for me.


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Given what you have told us, I'll be shocked if this is a MAF issue, be careful cleaning it. Typically just a shot of compressed air will do as they are pretty sensitive.

 

[_Broken_WRX_]

Ok is that the same thing as reflashing? I tried that a couole weeks ago and it actually seemed to help the car at least at idle. Maybe this rear O2 has more to do with it than I thought.
Thanks


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[Eagleye]

Ok is that the same thing as reflashing? I tried that a couole weeks ago and it actually seemed to help the car at least at idle. Maybe this rear O2 has more to do with it than I thought.
Thanks


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Yes you can do a reflash. When you do that, allow the car to idle for about 5 mins to get the idle trim worked out. During that time, see what your AFR is at vs. before the flash. If it is where it should be I would just park the car (if possible) until you get the parts you need as that should fix your problem. If the AFR is still really rich post flash, I would begin looking for leaks.

 

[_Broken_WRX_]

Yes you can do a reflash. When you do that, allow the car to idle for about 5 mins to get the idle trim worked out. During that time, see what your AFR is at vs. before the flash. If it is where it should be I would just park the car (if possible) until you get the parts you need as that should fix your problem. If the AFR is still really rich post flash, I would begin looking for leaks.

Ok, Ill keep this thread posted once I get the part. Thanks


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[Batmobile_Engage]

Im going to clean my MAF today but Im not sure what that will really do for me.

This is ALWAYS a good idea when troubleshooting. Just be very careful.

Ive tried clearing the code and it doesent really seem to do anything. Im having a hard time finding the right part for the rear O2 I tried to make a harness for it and its getting signal from the rear sensor but its still throwing the code for some reason. Subaru is supposed to have the part I need back in stock by may though so I will get it as soon as I can.

https://www.ebay.com/itm/O2-Oxygen-...282807&hash=item3b287e97ed:g:DswAAOSwQmZajNYp

 

[_Broken_WRX_]

So I got the harness in and its no longer throwing the code but my issue persists. What should the MAP sensor read at idle? Mine is around 4.7 psi I feel like that is really low.
Thanks


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[Eagleye]

After installing the new harness did you reflash?

 

[Batmobile_Engage]

So I got the harness in and its no longer throwing the code but my issue persists. What should the MAP sensor read at idle? Mine is around 4.7 psi I feel like that is really low.
Thanks

I am NOT sure on this one, but I do think your MAP sensor should read ~5 psi at idle. This is because the engine is drawing a bit of vacuum at idle. I believe that if you were to stop the engine (but leave the key on) and read the MAP output, it should be roughly 14.7 psi.

After installing the new harness did you reflash?

Definitely reflash. Or better yet, full ECU reset. Either via an Accessport or manually.*

* Disconnect positive battery terminal. Place a rag or plastic bag over the post to prevent inadvertant contact. Get in the car, turn key, bump brakes. Let sit for 2-3 minutes. Reconnect battery and start engine. Engine will most likely take longer than normal to start, so don't freak out.

Drive carefully and observe for any reoccuring problems.

 

[_Broken_WRX_]

I just reflashed and it didnt really seem to do much except idle a little rougher. What else should I check? Plugs maybe?


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[Alin]

First thing's first, have you performed a boost leak test yet?

If this issue began only when the TMIC was removed and put back on, then I'd imagine it being one of two points: the throttle body to TMIC coupler or the turbo to TMIC coupler. A third would be the y-pipe, but I'm assuming that wasn't messed with. It would have to be a mechanical issue if the car was fine beforehand.

Looks like you have a Cobb AP. I'd suggest you monitor some parameters and check if anything seems to be off regardless, but you really need to perform a boost leak test first.

You can monitor things like, but I don't know if it'll help:

(You already mentioned AFR was whack.)
-Roughness Monitor Cylinder 1
-Roughness Monitor Cylinder 2
-Roughness Monitor Cylinder 3
-Roughness Monitor Cylinder 4
-Injector duty cycle
-Injector Pulse Width
-Injector Latency

Do you have a wideband installed post turbo in your downpipe O2 bung?

You can also check the physical spark plugs, coil packs, any loose connections around the engine bay. The intake, turbo, EBCS, and other various connections.

Honestly, you have to begin with a boost leak test! It's extremely difficult to suggest things form behind a computer screen.

Get us a video or some pictures of the engine bay in the meantime as well.