Classic P2188 (Too rich at idle) code

ryanz1243

ryanz1243

Greenie N00B Member
Greenie Member
I have a stock diameter Corksport ram air intake and BNR S1. It is on the stock Cobb map (should be same as Mazda OEM afaik). Everything else is bone stock. I only run 93-octane fuel.

I'm getting P2188 (Rich at idle) and can verify it idles rich, at least if the AC is off... either way, LTFT is a bit high and/or all over the place, but always positive.

My current plan is to replace the spark plugs which are getting pretty old according to those who change them religiously. Other than this step, I'm all ears for suggestions on how to fix this. A lot of other threads end in people seemingly replacing half their intake and then giving up.

Also, attached are several logs with descriptive titles. All were taken today with 85 F temps outside. Hopefully something in there is helpful.
 

Attachments

Change your oil and see if the fuel trims correct. If they do your high pressure fuel pump is probably leaking into the crankcase system causing the oil to dilute from fuel.
 
If your plugs have less than 50 k miles just check the gap
 
Awafrican said:
Have you done a boost leak test? Because I would, Also Cobb stage 0 is their simulated stock map not 1.
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I did say I was on the stock Cobb map. I have not tested boost leak but why would boost leak cause rich at idle? There is no boost to leak at idle.
 
ryanz1243 said:
I did say I was on the stock Cobb map. I have not tested boost leak but why would boost leak cause rich at idle? There is no boost to leak at idle.
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Sorry re read it and I just have seen the s1 and defaulted to stage 1 cobb map.

Because there's still a vacuum at idle and if air can get out in boost it could get in at idle. The last and only code I've ever had I was getting at idle / light driving and a boost leak test showed me where the leak was, I thought it was good. Depending on where the air is entering or exiting car will adjust and there's your code.

Also clean your MAF sensor and check the oring on it, my corksport maf housing has claimed 4 orings until I sanded the area where the oring goes in with 400 wet grit. That oring when it failed always caused some wacky fuel trims and boost test was good, only caught it because I was cleaning my maf
 
Awafrican said:
Sorry re read it and I just have seen the s1 and defaulted to stage 1 cobb map.

Because there's still a vacuum at idle and if air can get out in boost it could get in at idle. The last and only code I've ever had I was getting at idle / light driving and a boost leak test showed me where the leak was, I thought it was good. Depending on where the air is entering or exiting car will adjust and there's your code.

Also clean your MAF sensor and check the oring on it, my corksport maf housing has claimed 4 orings until I sanded the area where the oring goes in with 400 wet grit. That oring when it failed always caused some wacky fuel trims and boost test was good, only caught it because I was cleaning my maf
Click to expand...

I replaced MAF O-Ring and cleaned the sensor. I also did a thorough check of the intake side, re-doing clamps and cannot find any leaks. Code will not go away and fuel trims still are garbage. I haven't had the time to do a check of the exhaust but probably will this weekend.

In addition I'm now getting P2177 - Too lean at off idle. So my LTFT's are almost always >+10, STFT often negative, it's rich except for when it's lean. I'm pretty lost here.
 
Did you reset your fuel trims after checking everything and drive ~20miles? Otherwise it'll take forever to come back to normal. Yes could be an exhaust leak or even a failed o2 sensor, did you actually do a boost leak test?
 
Awafrican said:
Did you reset your fuel trims after checking everything and drive ~20miles? Otherwise it'll take forever to come back to normal. Yes could be an exhaust leak or even a failed o2 sensor, did you actually do a boost leak test?
Click to expand...

That was the problem. Reconnected the battery, now trims within +-5. Thanks for the help.
 
ryanz1243 said:
That was the problem. Reconnected the battery, now trims within +-5. Thanks for the help.
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Sweet, the resetting of fuel trims (battery disconnect or reflash map) and driving is key otherwise it take forever your the ECU to relearn everything
 
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