Thread: My new FR-S!
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Old 06-23-2015, 04:52 AM   #35 (permalink)
serialk11r
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spyder2 - '00 Toyota MR2 Spyder
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Quote:
Originally Posted by BabyDiesel View Post
Have you considered bleeding voltage from the MAF as it is going to the ECU? That is how Tygen1 enabled lean burn on his 98 ZX2.

Of course, you have a completely different beast. It is still worth a shot to see if it is possible!
The problem here is that the post-cat O2 sensor is the final authority on fueling, and it's a narrowband sensor that can't be manipulated through software. I can change anything I want, and people do change MAF scaling as well as O2 sensor scaling (useful for turbo setups where the stock sensor's inaccuracy can be a problem), but at the end of the day at cruising conditions the post-cat sensor will figure out what stoichiometric really is and whatever scaling you set on the MAF or wideband O2 will be reverted in the long term fuel trim.

I just flashed my car with the -15 deg intake map though, and the logs say the engine is cooperating! I'm going to try -20 deg on the way back from work, but I may be running out of VVT adjustment range. I set the entire AF compensation table to positive and the engine now likes to run slightly lean more often. I'm really really hoping these changes can get me to 45mpg cruise.
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