prodigy215

I have a 04 F150 5.4L, Vin #: 1FTPX14504NA94041 . I have 2 Bad Sensors my mechanic said (Bank 1 & Bank 2 lean), i rather just replace all the sensors and get it over with. I did research and I see its a few different part numbers for the O2 Sensors. How do I know which are the correct sensors to purchase to replace all Four of them?? Reply asap, thanks!

http://www.fordparts.com/Commerce/Ca...0Sensor#Search

otto457

Both banks lean usually isn't the O2 sensors. Clean the MAF and check all your vacuum lines.

ellis4pa

If im correct, you want the two upstream O2 sensors, they would be the ones controlling the air fuel mixture. The downstream ones are to monitor the catalytic converters. Which is why there are different part #'s, driver side and passenger side will usually be different as well. The only real difference is the wire length, between the two not the sensor itself.
As far as which part numbers? We gotta know what brand your looking at, each brand will have a different part number, or you can just call your parts store. They should be able to get it right, and if not they will exchange it for the right part


But i agree with the poster above, both sensors going bad at the same time is almost unheard of. Check your intake side first.

You wouldn't happen to have an aftermarket cold air intake would you?

prodigy215

Thanks for reply guys. No i don't have a aftermarket cold air intake. Question! When I unplug the MAF Sensor, the truck shuts off. Also when I start truck back up and plug the MAF Sensor in, it also shuts off. What problem could this be?? Does that mean the sensor is bad? I just replaced the two upstream sensors

ellis4pa

No! Please stop doing that!

The maf sensor uses a heated element to measure air volume, sudden changes, like plugging and unplugging while your engine is running, is not good.

Get a electrical parts cleaner, or maf cleaner, there the same. Use nothing else, after the truck has been sitting for 20 min or so unplug and take the maf out, spray it down real good. Put it back in, and wait about 5 before plugging in and starting. Because it uses the heated element it can be very fragile while hot.

ellis4pa

After you clean that, and the throttle body, if you still have an issue, check for air leaks in the intake, from the intake manifold out.

Especial86

iTrader: (1)

X2^^^^
The unplugged MAF shut down the motor because it working properly.
The two 02 sensors are throwing codes because they are also working properly..
Try what ellis4pa suggested in his posts and then start from there... This will probably fix your issue.

prodigy215

Ok thanks will do! Im going to clean MAF & Throttle Body first thing tomorrow morning, will give update. Appreciate everything

prodigy215

I have cleaned the MAF Sensor, Throttle Body and checked the vacuum lines and I notice a wire seem like it was cut. Are you guys able to detect what kind of wire/line that runs to?? My truck still shakes alot at idle & cuts off. Also when i make sudden stops rpms drop really low and sputters. I posted a pic of the wire below

Especial86

iTrader: (1)

That looks more like a vacuum line to me...