P0171 & P0174 where to start?
Thread Starter
On The Tree
Joined: Jun 2019
Posts: 148
Likes: 29
From: Atlanta, GA
P0171 & P0174 where to start? I'm showing these codes for "system too lean" both banks. No cats or rear O2s. Fronts are new. Car is definitely not running lean, AFR is dead on at idle, cruise and WOT. No obvious exhaust leaks. No drivability issues at all. Car idles fine and pulls hard. Injectors are 42lb green tops just serviced and flow tested, fuel pump is a brand new racetronix pump w/ hotwire kit.
Given it's both banks I doubt the O2s are to blame. The car was dyno tuned recently and pulls hard to redline so I don't think I have a fuel pressure issue either. I was thinking I'd clean and then maybe replace the MAF. Are there any common spots to start checking for vaccum leaks? Anything else to look for?
Much Appreciated.
Given it's both banks I doubt the O2s are to blame. The car was dyno tuned recently and pulls hard to redline so I don't think I have a fuel pressure issue either. I was thinking I'd clean and then maybe replace the MAF. Are there any common spots to start checking for vaccum leaks? Anything else to look for?
Much Appreciated.
I'm guessing within the tune the rear o2's are turned off? I would clean the maf with maf cleaner or rubbing alcohol. Just let it dry 100% before turning the key. Clogged fuel filter or weak pump? Injectors bleeding off? Fuel#regulator? Check your plugs and live data. Make sure computer is getting the correct readings and not a sensor issue. If its running differently, unplug the maf... Then drive it. At idle will surge... But unplugging maf throws it into speed density.
