P0101 and P3700 question
 

This is my first true "issue" with the car in almost 4 years. I had my oil changed at the dealership this morning and after leaving and making my next stop I got back in the car and turned it on to see the cel. I checked the dipstick and saw the oil was low so the dealership sent a tech down with oil to get it normal and we drove back to the dealership(10 miles away). And I've never had an issue with the service from this dealership since the day I bought it from them.

Once back they drained the oil and filled it again, then scanned the codes and said it came back the o2 sensor. Once I got home I plugged in my OFT and checked the codes myself and got these codes:
Attachment 153197
P0101: MASS AIR FLOW CURCUIT RANGE/ PERFORMANCE PROBLEM
P3700: ?

And YES, I searched the codes and tried to find any related issues but didn't have a lot of luck. Just led me to this site with a list of codes:http://ft86tech.com/frs-brz-error-codes/

I still have the car, but noticed the shifts feel harder when the car downshifts. I'm not sure if I should try to replace the mass air flow sensor or just wait and let them replace the o2 sensor first and see where that gets me? Would there be anything I need to watch for before or after it's replaced?

Any input would be greatly appreciated!!

Ensure maf sensor on intake tube is plugged in correctly, check for vacum leaks or hoses not connected. The other code seems to be a weird emissions code which may have triggered.

If all looks ok reset codes, drive sedatly and se if they return, they may have been stored codes

It does not look like an 02sensor issue

Hoever look at your ltft see if its high like above 10% anytime.

Also check comanded afr vs afr during wot runs and see if they are close
High fuel trims are usually and indication of fueling issues

Thanks for the response!

I ran a few logs with it and tried to get them in datazap but for some reason it wouldn't generate the actual charts for me. But the ltft's ran up to 10 or 11 a few times but was kind of all over the place between 1-10 and sometimes negative. I didn't have it logging commanded afr though.

I've never adjusted any of these myself as I had a tune from shiv, should I try the stock tune or a ots tune instead of the custom tune from shiv and see what changes?

I'll keep trying to get the datalogs to show up and add it if i can.

From past experience, check your oil before you leave the dealer. It can be overfilled, under filled or they leave a cap off something.

I bought a 99 4-matic wagon that the dealer overfilled at the first oil change....they had to replace the catalytic section of the exhaust. The kid didn't know the motor took less because of the oil pan design was different for the all wheel drive version. I made the sales manager take me to lunch instead of refunding the extra quart of Mobil 1))

Oh I will be from now on that's for sure. They told me they drained it and I checked it in front of them before I left. The service adviser I've always worked with was not very pleased with the tech that originally serviced it.