Troubleshoot with AFR's

I was tuned (again) by Bren about 3 weeks ago with perfect numbers. Since then the following series of events...

 

1. My invidia broke a weld at the header flange.

2. Fixed #1 and found a loose turbo cartridge per missing bolt and exhaust leak at the DP flange.

3. Fixed #3 using services from Agile performance in Fallston, MD

 

Now have rich (at least according to wideband data) AFR's (14.0-14.3) at idle.

 

This matches the stock narrowband. Also shows 2.1% learning in AF Learning 1A.

 

Everything seems to be good but I don't like the rich reading so I need some help troubleshooting.

 

Bren is unable to troubleshoot further without seeing the car and more data.

 

Thanks in advance!

Subarus idle rich. 14-14.3 is normal and AF learning of 2.1% is well within the 6% most say is acceptable.

When it was tuned originally, it was closer to 14.7 at idle.

 

I'm aware that the fuel learning percentage is normal, it was more of a comparative parameter to say, "if this is good why would it run rich".

 

Im a science teacher so anything that's not stoichiometric concerns me a bit.

 

Thanks for the quick input! Very much appreciate it!

I am not sure why it was running at 14.7 idling, even 100% stock Subarus idle rich. When I was stock I was usually 14.1-14.3. Now I'm stage 3+ and still idle at the same. If the car wanted to idle at 14.7, it would and you would then have very high AF learning numbers to get it there. When cruising it is more around 14.7, and of course under boost it should drop way down to the 10-11's depending on what the tuner likes to see

I'm stage 3 also, just wasn't sure. Before my mechanical issues it seemed to be closer to 14.5-14.7.

This thread may help you a bit: http://legacygt.com/forums/showthread.php/interesting-afr-behavior-idle-213454.html

 

You can jump to post #22 for a direct solution that may work for you.

 

My cars at stock and even stage 1 and 2 would idle around 14.2-14.3. I pointed my tuner to the above thread. He made the changes and both of my cars now idle at 14.7.

Interesting. My only concern would be why does Subaru want it to idle rich and what are the side effects of leaning it out to 14.7

^ I have no idea why that is .

Interesting info for sure. I may end up doing a header at some point which means I'll need retuned anyway....you know how these things go. Besides, rich is better than lean.