P0172 and P1170 Codes
 

Hi, I recently had a check engine light pop up, and got the code read. The codes were P0172 (System too rich bank 1) and P1170 (Fuel performance/Port injector) But I decided to be responsible and take it into a shop. They told me that I needed to replace my AFR sensor, as well as my MAF sensor, also said that an oiled filter may cause the issue. But they quoted me $1400 for the repair so decided to do it myself for around $300 and replaced the air filter because it needed to be changed either way. It turns out that it was not the problem, and figured it may not have to do with the sensors being broken, but the sensors sensing something is wrong. Especially since I sometimes smell gas when I am driving. I was wondering if anyone had any suggestions or history with this issue before I try some more of my options.

the lambda could be the culprit, as well as bad exhaust leak or faulty injectors

I suspect it could be the injectors because of the smell of gas as well as a rough idle RPMS also tend to drop even stalling at some points

yeah
what you can do for now is check the 3 bolts of DI ecu inside bonnet near the big fuses box are fully tightened to.ground

Make sure that MAF sensor is removed and doused with cleaner. Also, you might need a fresh air filter if your oily one inadvertently fouled the MAF sensor and possibly restricted flow.
Regarding injectors, no experience there.