ROCNDAV

iTrader: (100)

I started getting these 2 codes after I did the FRA mod.

Do I need to tune for this mod?

I've searched, but almost all the threads are after installing header. My car is stock, other than a lid, filter & FRA. I have about 65K miles on it.

I sprayed carb cleaner around the intake a connections to see if I possibly had an vacuum leak, but I never noticed a change in the idle (or sound).

I am going to look for my fuel pressure gauge and check the pressure. Wanting to see if there is anything else that I should/could check.
I doubt that 2 O2 sensors went bad at the same time, nor plugs on both banks.

Any ideas?

FiredUpZ28

When you have a code it helps to look it up so we know and don't have to go searching.... but a PO171 and a PO171 is a lean code for both banks - I wouldn't be looking 02 sensors if they are both lean. I would do a fuel pump volume test if possible and check your fuel filter as well. Check anything fuel related from the rail back or possibly bad signal from the MAF. If you can, get some rubbing alcohol and a Q tip and very gently clean the MAF wire. You didn't de-screen your MAF like some dumb ***** did you?

ROCNDAV

iTrader: (100)

Sorry about not posting the code description, I guess I had all these search threads about P0171 & 4 open that I forgot to put the description.

The MAF is not de-screened, its all stock, other than the FRA & SLP lid.

HP Tuners shows the LT B1 & LT B2 in the red with a reading of -25% each.

Rob@EFIAlchemy

iTrader: (9)

do you have a k&n? if so did you just recently clean it and reoil it?

ROCNDAV

iTrader: (100)

I do, and I don't remember if that is when the problem started. Why? Does the oil on the K&N mess up the MAF?

FiredUpZ28

If enough of it gets on the hot wire of the MAF, yes.

JonCR96Z

iTrader: (33)

Yeah, try cleaning the MAF and not oiling the filter as much. I've actually had a similar problem, but mine was too rich and took out one of the 02s.

ROCNDAV

iTrader: (100)

so, should I try putting a paper filter back in, clean the original MAF and putting that back in?

I should only wipe the wires with an alcohol dipped Q tip swab?

JonCR96Z

iTrader: (33)

Get some sort of spray cleaner (brake, carb, electronics) and just spray the wires off, don't touch them. Then try it.

Rob@EFIAlchemy

iTrader: (9)

get some electronics cleaner or alcohol put it on a qtip and be very careful and clean it, if you break one of the wires the maf becomes no good. you should be fine with your k&n just watch the amount of oiling you do, just has to be light.

ROCNDAV

iTrader: (100)

Well, I found the problem. It was that rubber 45 degree elbow between the Intake and what I believe the vacuum check valve. I checked it before, but it was actually torn on the bottom side. I taped it up until I can find something to replace it with.