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Old 12-12-2012, 11:33 AM   #23
Scooby Specialist
Member#: 245218
Join Date: Apr 2010
Chapter/Region: South East
Location: FL
2013 STI Limited


Originally Posted by dsm_luck View Post
The thing is disabling the 02 shouldn't be an issue because the car ran for 10k on this tune without a hitch. If disabling the rear o2 was an issue it should have given me bad trims from day one right? Also my car is catless. I actually saw the moment when the trims went bad as I was driving. No noise no change in the way it drove. The fuel trims just crept way lean and stayed there. Odd to say the least.

This is what is not making sense to me.

- A/F learning shows +5 to +25% just about everywhere. So that would mean the ECU is pushing fuel to prevent a lean condition.

- Meanwhile A/F correction is usually showing low end negative numbers. 0 to -10%. Ecu pulling fuel?

- Keep popping a p2097 post catalytic system too rich. This disagrees with the A/F learning (ecu says running lean) and even the A/F correction. I will pop this code even if I don't boost.

- Car drive exactly like normal. No weird idle, no hesitation, no pops, not a hint of knock, hits nearly dead on with the Maf g/s before the issue. Only way I would know there is a problem is because I was monitoring the trims and because the cel keeps popping.

So how can this be? It contradicts.
-the Rear O2 does affect A/F corrections AND A/F learning.
-Your A/F corrections(short term or immediate fuel corrections) are affected by the "tip in" table. This may need to be adjusted to better work with your injectors. This would explain the difference in your A/F corrections(short term trims) and your A/F learning(long term trims).

Based on what you explained, there seems to be something more like a mechanical issue causing these problems. A wideband will help here.
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Tripintaz is offline   Reply With Quote