So my Service engine soon light came on and checking it with torque pro it came back with 2 codes-both bank 1 and 2 powertrain too lean-(its a 2009 G37 with intake and exhaust upgrade, although I got those done 2 years ago) I would normally just take it to the shop to check it out, but I did get an UPREV tune about 2 months ago and he leaned out the AFR. Im thinking since its both bank 1 and 2 its not an air leak or both O2 sensors bad?

Monitoring with Torque pro the AFR jumps around 14.60 to 15.00 normally. When I stomp on the gas hard it does go down to around 12.50 to 13.50 momentarily before I left off the gas and goes back to around the 14.70 range. But its been like this since I got the tune and the SES light just came on.

But I wanted to ask some advice, should I just take it to the dealer and let them know I got a tune or try and take it back to where they did the uprev to see if he leaned it out too much? The shop I got it done at is kinda far from me which is the reason Im asking for advice first.

Thanks everyone!

 

You already said that the tuner himself leaned it out, so that is why those codes appeared.

Just go to your tuner and tell him about the problem. He can shut off those engine codes with Uprev.