I just recently purchased a e.g. with a h22 swap, and while driving it home today i noticed that the car is running extremely lean at idle indicated by the dashes, idles fine though. Cruising on the highway at about 80mph rpm at about 3500 AFR hovers around 11-12.0 at wot its at 10. So my question is what is the problem?Upon reading around some have said it could be a exhaust leak that could cause the lean condition at idle, is that also the reason why it is running rich at WOT and cruising? Any other suggestions on what the problem could be?

Also the wideband is new.

 

Alright guys, so i thought the issue was a pretty bad exhaust leak i had at the header to down pipe flange. I fixed the leak and proceed to turn on the car to check if my AFR is in a normal range, turn on the car and it goes full lean "three dashes", drove it around the block a little bit to warm it up a bit and the car reads full lean at all rpm ranges. The car doesn't stutter nor does it hesitate on throttle. Although i do get some backfire off throttle. Any suggestions would be helpful.