P2177 - System too lean off idle

Grommish

Member
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06 BCM Speed6 GT
Ok, so out of nowhere the CEL pops on, and tosses me a P2177. I know its a lean code, however, there isn't much on here about it.

I do have a SRI, but I've been running it for almost 9 months now without issue. This is THE first time the code has popped.

I'm pulling 20Vac on the guage, so I don't think its a vac-leak. Any other suggestions? I'd rather not throw the stock air-box back on, but of course will if that is what it takes. The SRI is a no-name that I got from a friend of mine who was running it on his CX7 for years without an issue either.

No bogging, no hesistation, no physical symptoms.

Suggestions?
 
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I was getting that code, and the on-idle one, when I had a very small vacuum leak. You my want to invest into vacuum testing everything before the turbo. IIRC, if there was a leak somewhere between the IC and IM, then you'd be running rich, as you'd be losing air, so this leak has to be somewhere between your MAF and the turbo... not much distance, I know, but definitely worth checking/reclamping.

Are you using any kind of tuning solution?
 
Yah.. I can certainly check that easy enough. Like I posted, the vac guage is showing 20vac at idle (like it always has), but *shrug*. I don't have idle issues or hesistation or det.. so.. Its odd..

Nah.. No tuning, the car is basically stock as far as the engine goes. The SRI (again, been on a while) is the only change for it other than the line for the guage.

Thanks for the reply!
 
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Then yes, definitely check intake/inlet everything. If that's not the case, we'll have to start brainstorming in this biatch ...
 
I just had that code for a while, it was because my LTFTs were 20.3% at one point. Which I believe automatically triggers this code. Car still drove perfectly but since the computer had to compensate >20% it popped up. Do you have a Dashhawk to check?
Once I fixed the problem it instantly went away.
 
I just had that code for a while, it was because my LTFTs were 20.3% at one point. Which I believe automatically triggers this code. Car still drove perfectly but since the computer had to compensate >20% it popped up. Do you have a Dashhawk to check?
Once I fixed the problem it instantly went away.

No DH. Eventually I'll get an AP, but its a ways off.

So I checked all the vac lines I could see and did a propane test (unlit torch around the engine bay, waiting for the RPM's to jump) and got nothing. Threw in a bottle of injector cleaner, just in case I've got gunk, so I'll see if that does anything.

Nothing was loose. I kicked the negative cable to reset the PCM and the LTFT, got about 40 miles and it popped back on. Ugh..

Digi, what was your issue that caused the Longterm to spike?
 
Well I had a Mazdaspeed CAI installed in my car, and I was in the process of swapping it out for a Cobb SRI (to be compatible with an OTS AP map) and I noticed a giant rag lodged next to my filter from last time Mazda had their hands on my car... Now I'm not sure if the CAI didn't agree with my car since it was untuned (I've heard a lot of people getting between 14%-20% ltft's with this cai), or if it was the rag, but with the SRI installed my trims dropped down to <10% untuned.
There is a chance your SRI made your fuel trims jump an extra percent (your buddies car may have been running at 19%) or two to hit 20% where the CEL automatically lights. I'm no pro but I just dealt this with problem last week, so if all the simple tests and fixes don't work, maybe try the Cobb SRI.
 
Well I had a Mazdaspeed CAI installed in my car, and I was in the process of swapping it out for a Cobb SRI (to be compatible with an OTS AP map) and I noticed a giant rag lodged next to my filter from last time Mazda had their hands on my car... Now I'm not sure if the CAI didn't agree with my car since it was untuned (I've heard a lot of people getting between 14%-20% ltft's with this cai), or if it was the rag, but with the SRI installed my trims dropped down to <10% untuned.
There is a chance your SRI made your fuel trims jump an extra percent (your buddies car may have been running at 19%) or two to hit 20% where the CEL automatically lights. I'm no pro but I just dealt this with problem last week, so if all the simple tests and fixes don't work, maybe try the Cobb SRI.

Perhapse. I've been running this SRI for 9 months now, through the winter AND 14 days of 90+ degree heat here in Cincinnati. That's what makes this frustrating, as there is nothing I've changed or done. Meh! I'm gonna swap back the stock box and see what that does..
 
Update:

Swapped the stock box back on and cleaned the MAF, code hasn't come back yet. I'm wondering if it was a combination of the higher LTFT's associated with the SRI's plus a slightly dirty MAF causing it to spike above the 20% threshhold.
 
Ahhh that must be it then. Good to hear you found the problem and glad I could help! I guess you can either try a different SRI, or stay stock and get an AP in the future.
 
what kind of SRI were you using? i am currently using AEM CAI and i had the same code. i had some assistance with tuning through COBB to compensate, but now the car smells rich due to that and i can even smell it inside the car. i am thinking of going to Corksport SRI.
 
Honestly, it was a no-brand one that worked fine for a few months before I got the code. I returned to the stock box and cleaned the MAF and it went away.

That being said, I experienced it again under the stock box while on a trip from Cincinnati to Eastern PA. I was getting on the on-ramp to the Interstate and romped it to get to speed, it bogged, went into limp mode, and threw the same code. I sat on the shoulder for about 10 mins, cleared it with my scanner and continued on my way without the issue returning.

The only thing that connects the two incidents was the gas. Both times I had put Kroger gas into the tank.. I've not been back since.. The engine doesn't seem to like it, as I've got a buddy who owns a CX-7 have this same issue (with the same gas).

I've been sticking to BP or Shell ever since, no issues..
 
Small update:

After putting the stock airbox in, I'm still get the Lean code. I've determined in caused by my driving style.

I've got a FAO (Fixed Ankle Orthotic) on my right leg, which means no ankle movement (movement comes from the knee). Since the Speed6 has such a sensitive throttle (DBW?), I'm actually leaning the A/F during normal driving. Letting the wifey drive, or me romping on it, causes the CEL to clear..

I've got no idea what to do now, but I'm also not sweatin it like I was. Thanks to everyone who offered suggestions!
 
Necro-Bump update:

I finally threw a second code. So I was throwing a P2177 and a P2188. These two in combination directed me straight towards the TSB on the bad factory Upstream O2 sensor. If I had cracked, it was a hairline and then decided to give up the ghost. At no time did I ever get a CEL for the Sensor itself.

Dealer Price: $240
RockAuto: $105 shipped with my 5% discount.

Replaced the Upstream with a NTK Wideband OE replacement and by Jesus, it works swimmingly! I was second owner for the car, and this is the first time I've truly experienced "Mazdaspeed".. I spool in first and second now (didn't before) and I don't hit fuel cut during WOT (happened only occasionally). That almost inperceptable hesistation/stutter is also gone. Outstanding results.
 
The connection between the Intake and the TIP was not flush with the stop, but still on securely. I pulled it apart and re-tru'ed it against the stop and tightened it down. It's been three days since the reset and CEL is still off.

Here is to hoping.
 
Asking a quick question regarding your post.

I just had that code for a while, it was because my LTFTs were 20.3% at one point. Which I believe automatically triggers this code. Car still drove perfectly but since the computer had to compensate >20% it popped up. Do you have a Dashhawk to check?
Once I fixed the problem it instantly went away.

Hi, I wanted to know what you changed because my LTFT is at 20.3% as well? I cant seem to get rid off P2177 and my freeze frame showed LTFTs 20.3%. Can you please help.

Thanks!
 

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