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Discussion Starter · #1 ·
So I'm running stage 2 93 oct map v320 on my 2013 st, with cobb intake and filter, fmic, and cat-back. Almost every time it rains i get a check engine light and it's a code for the first bank o2 sensor and it says it's running too rich and i can smell the converter. So this only happens when it's very humid out. I recently changed to a colder spark plug and it still happens as i figured it would, it probably made it worse.

Anyway my questions are,
Is this a common problem? Does an updated map fix it? Should i get it tuned? Will a hotter plug be better??

Any advice would be greatly appreciated, thankyou
 

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This isn't going to be a lot of help but I ran that tune for a while with more or less the same mods and no issue like you have. I have also regularly updated my AP and the tune.
 

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As @shineboy implied, update your AP to v400. Also, the issue could be fuel or fuel pressure related. Check the IC hoses too. If the clamps are stock, they are notorious for becoming loose over time. Since you said that the issue occurs predominantly when it's wet outside, moisture is getting in somehow. Lastly, the O2 sensor might be bad.
 

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As @shineboy implied, update your AP to v400. Also, the issue could be fuel or fuel pressure related. Check the IC hoses too. If the clamps are stock, they are notorious for becoming loose over time. Since you said that the issue occurs predominantly when it's wet outside, moisture is getting in somehow. Lastly, the O2 sensor might be bad.
I never threw a code for being rich but I threw lean and "o2 sensor slow response" after changing out my DP. All I did was purchase new o2 sensors and swapped them out and haven't had problems since. IDK if it will work for you because I dont see a mod on your list that really tampered with those parts. Most of the time those parts fail because they were tampered with or moved to a new DP.

Another thing I would consider is maybe an injector is stuck open? Some people on these forums have experienced injector failure and if your injector was stuck open, it could very well be flooding the cylinder with more fuel than it needs. Just some thoughts.
 

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Discussion Starter · #5 ·
Thankyou for all your input.. i forgot to add, the check engine light only comes on when i let the car idle for a while, so humid and idle are the key factors..
 

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Discussion Starter · #6 ·
Just an update, I figured out when i was putting my down pipe on, reaching behind my cobb intake, that was already on the car when i purchased it, to disconnect my O2 sensors that the big vacuum hose that connects to the intake was not attached. I'm guessing thats why i was running rich. Hooked it back up, installed my catless dp and put my maps on stage 3 and havent had a problem sense..
 

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Discussion Starter · #8 ·
wonder how much dirt your turbo chewed up? that sucks!

This is why not just anyone should be opening up the hood on their car.
First thing i thought too. I bought the car from a dealer and it already had cobb stage 2 on it from previous owner, he never mounted the IC properly either, didnt drill holes to bolt it on and didint take out the shutters, he just kinda cut the shutters and slid in the IC. I had to fix that also. Unfortunately didn't notice this vacuum hose until i drove the car for like 5 months.
 

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Discussion Starter · #9 ·
So little update, I still get the code and it seems to only happen when it's humid out, my car will also pop alot when it happens when coming to rolling stop in gear, because it's running so rich... I am fine for weeks then one rainy day and i get CEL. Any ideas? I dont think its a vacuum leak. I was thinking bad O2 sensor but wouldnt it CEL all the time. I was also thinking MAF sensor might need a cleaning, maybe reading the wrong humidity, or access port maybe ****ed up my ECU, i have no idea.
 
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