My check engine light just came on, and I'm getting the error code that Bank1 and Bank 2 are running lean. If I were to replace my O2 sensors, what is the best sensor to use for a replacement? O.E.M. or Autozone's universal? It's for my 04' 5.4 F150.

 

It's most likely NOT an O2 sensor problem. It's probably a vacuum leak. Have you recently done any modifications/work to the engine? You could try cleaning your Mass Airflow Sensor, ESPECIALLY if you have an aftermarket air filter.

 

Listen to this man, heed his words.

O2 sensors are tattletells- if you're getting lean codes, you need to start looking for unmetered air getting into the engine. If this is a 5.4 3V, have you installed an aftermarket intake? Sometimes, without tuners to go along with them, aftermarket intakes may set lean codes.

 

Yeah, I've installed an AEM Brute Force Intake, Helix Throttle Body Spacer, and an Edge Evolution Programmer. The light came on a few days before I installed the programmer so I'll look at all of the connections to make sure there are no leaks. I'll also check the MAF. Thanks for the input to lead me in the right direction.

 

If I had to guess,I would look at the tb spacer.

 

my guess is the intake

 

if your getting 171 174 codes , your o2's are reporting as they should be - there doing there job, there fine..

Quintins right..

 

I had a "too lean" error code once (I don't remember the number). Someone told me possibly a loose gas cap once.

I disconected the battery to reset the computer. Never got another error code.

Good luck. Edog

 

Not even in the ball park. A gas cap cannot cause these codes.

Steve

 

After I installed an aem intake. My truck started showing leaning codes. This was last week when I install. Today I looked at it and found that the temperture sensor was a little loose. I notice at the time of install but figure that was just the way it was. So today I made it permanently attached and no more leaning. At least not for the time being. So give it check and see if maybe an air leak. I also hooked up the scanner to see the numbers. At max airflow was at 15lbs/min, temperture was at 51f. Does anyone know the factory setup numbers.

 

Yep, the IAT grommet is the first thing to check, along with all your intake connections. You work you way back to the PCV valve by the firewall.

 

After installing AMI my coil packs started going. Maybe it was just time, but could more air make the computer make the coil packs produce a higher voltage spark? Might be a stretch but thought I'd ask.

 

ricochet97 that's along stretch, 'cause I bet you didn't reset your ecm after the install...










rockcoastie, did you get a custom tune with that intake?? if not that's the reason for the codes, now remove that intake until you get a tune on that truck...

 

Jereme, I think Rock has blown that engine already. Did you see the dates?

 

Alright WHO resurrected this one lol.