Failed Inspection! Error code!

[joshheat25]

I failed inspection today for two error codes that I looked up online and it said that my "system was too lean in bank one and two".
does anyone know how to fix this I was assuming that I should use a higher octane I have and air intake and exhaust maybe I should use 93.

 

[6Stang7]

Too lean means that you don't have enough fuel in your air/fuel mixture. The octane rating has nothing to do with the problem. It's impossible for me to tell you what is causing this problem because there are way too many things it could be. Bad O2 sensor, bad MAFS, dirty injectors, ect. I assume you are talking about smog here, so can you post your outputs (hydrocarbons, NOXS, CO2)

 

[fiveofanatic]

Moving to tech....

What are the code numbers? What year car? (I assume it's a 4.6 Mustang.)

If it's '96 or newer it probably isn't the o2's, they've got their own codes. Lots of times it's vacuum leak(s) or a dirty/bad mass air meter.

 

[bdcardinal]

theres a common problem on fords where both the front O2 sensors show lean or rich, than you should check the Mass Airflow Sensor. also if you have a K&N air filter, it might be overoiled and that would gunk up the MAF.

 

[joshheat25]

2000 Mustang GT The codes were P0171 and P0174 Which are both System to lean in Bank 1 and then in Bank 2 what ever that means. I have decided it isn't the injectors because I just recently put injector cleaner and it has had this prob before. It might be the MAF is dirty or maybe a Vaccum problem around the intake plenum I am going to spray carb cleaner around the opening while the engine is running to determine whether this is the case.

 

[joshheat25]

I also was wondering if anyone had any ideas of what to do to quiet down my exhaust for the db test just a fix.

 

[bdcardinal]

what do you have for exhaust? and if you spray carb cleaner around the plenum you arent gonna go near your MAF. use electrical contact cleaner on the MAF, DO NOT USE CARB CLEANER ON YOUR MAF.

 

[6Stang7]

Do you have a copy of the test results?

 

[fiveofanatic]

Bank 1 is the pass. side of the engine, bank 2 is the driver's side. All data gives a couple of possibilities:

Fuel system:
*leaking/contaminated injectors
*leaking fuel press. regulator
*low fuel pressure or running out of fuel

Induction system:
*air leaks after the mass airflow meter
*vacuum leaks
*PCV valve/line leaks
*improperly seated dipstick

EGR system:
*leaking egr gasket
*stuck egr valve
*leaking diaphragm

Base engine:
*oil overfill
*cam timing
*cylinder compression
*exhaust leaks near or before the o2's

Personally, I lean towards vaccum or PCV leaks, or bad mass airflow readings. It's happening on both banks of the engine, so it's something that affects the whole engine, probably not something like an injector. Unmetered air entering the engine from a leak I would say is going to be more likely vs. a fuel delivery problem, though it could be fuel.

 

[Pitch4pd]

It could also be as simple as a computer update from ford. But I wouldnt do that first, if it is doing it on both sides I would try to ruleout the o2's they normaly go one at a time, odd to have em both go. Like everyone is saying check the maf, make sure it is cleaned out (use the proper stuff). You could just reset your computer, drive it for two weeks and hope the codes dont get set before you go back.

Charles