99blkfrc99

I'm curious so I will phase this as best I can. We will say car X has a cam, headers and 2 inch true dual exhaust. Car has been tuned with a 12.5 WOT air fuel. Then a 3 inch exhaust has been added, no tuning. Will the air fuel now be richer or leaner than 12.5. Or will it be the same? Thanks.

G Atsma

In the bad old carb days, it would likely have leaned out. But with EFI, using MAF and O2 sensors, nothing should change except power level.

99blkfrc99

I forgot to add it's not carb. I figured the O2's would eventually sort it out but was not sure. Thanks.