Background: I havent tuned anything since the mid/late 90s, but I was fairly competent on those and I think have a good understanding of the basics of ECM tuning. This newer stuff so much more complicated and hence the layup questions....
Question: Just installed a AEM wideband to integrate into the can bus. 2015 Corvette Z06. Works perfectly. However, I am getting AFR readings slightly lean, like 15:0 to 15.3 at idle. Computer is commanding 1.0 Equivalence ratio and in closed loop.
My understanding of the older cars is that unless something was wrong, then it was more or less impossible to make them run anything other than 14.7 / stoich in closed loop. I would assume the same here, so long as the car is requesting 1.0 EQ? I could adjust the MAF, but wont that just move fuel trims and I would expect to continue to see the slightly lean condition? Is there an issue, or is this not even worth mentioning? The only thing I can think is my factory 02s are in the header collector, and the wideband bung is further back by ~12 inches, but past the collector flange.... but I cant feel or hear any exhaust leaks.
Second question.... I want to get a flex fuel tune started up and going. I would assume a good starting place is the tune from a E92 PCM from a flex fuel truck??? Does it matter 5.3 or 6.2?