Trd S/C Afr question

Hey guys, newbie here! I have a 2014 Tacoma TRD Sport 6 speed with the TRD S/C, running the 2.825 pulley, and AFE intake with magna flow cat back. I recently installed the URD competition Y pipe, right away noticed some differences on the AFR guage. When I start the vehicle up cold in the AM it appears to be running very lean for about 30 seconds or so until I hear what I believe is the smog pump turn off.. at this time the AFR returns to the usual 14.6. Is this something I should be concerned about ? Also if I rev it hard in N, the vehicle will idle for awhile at 15.5, need I be worry about this? Normal closed loop operation and WOT appear to be ok.
Thanks for any input!

Ian

 

Usually they run very rich right when you start them. Your gauge is maybe calibrating at that point. Mine took the first 10 seconds to calibrate every time it booted up.

 

What are you calling "very lean"?

It takes a while for o2 sensors to warm up and read accurately and it's also going to depend on if your ecu is in open or closed loop.

 

Oh ok I see.. the AEM guage doesn't show anything for a little bit when I first start it up in the am. Before the Y pipe instillation it wasn't doing that and would pretty much read 14.6 almost all the time. I just assumed it was running lean because the only other time it shows blank is when I take my foot off the gas with the vehicle in gear the guage goes blank because no fuel is going into the cylinders at that time. It seems to have a slower response now too.. Before the AFR would resume to 14.6 almost instantly now I briefly see 14.9 before it returns to usual.. is any of this stuff concerning? Thanks for your help with this!