new here and have questions

[doehunter]

Hello
I have a 2000 Expedition with the 5.4 engine.
A few days ago the check engine light came on. Today I had the codes pulled and it was for lean right bank and lean left bank.
While I was at the parts store I discovered the oil filler cap was not installed.
I found it behind the grill and put it on.
I bought a MAF sensor and a can of cleaner. Later on when I opened the hood, disconnected the battery and took things apart. I discovered the stock MAF sensor was not there. The prior owner had installed a K&N filter and the MAF sensor was part of that assembly. I cleaned it and put everything back together.
Now it runs and no CEL, but it has only been a few miles. I have to get it inspected this weekend, so I'm going to try in the morning.
My question is, if the light comes back on, where would I get a new sensor?
I looked on line at the K&N site, and I didn't see any mention of selling the sensor there.
Do they go bad?
I looked for vacuum leaks too, and didn't find anything yet.
Engine is running good.

 

[brockncole]

Hi, I had a K&N CAI on my 2001 F-150 and just put one on my Expy. So during the installation you take the MAF sensor out of the air cleaner and put it on to the K&N part that hold the filter. That should be the original or an original replacement MAF sensor. I don't know if the MAF sensors go bad I would imagine that they would if they get dirty, but I am not 100% sure about them going bad.

 

[FordandPolaris]

From what I can understand, you have a K&N cold air intake, not just the drop-in filter, correct? Usually when a lean reading comes up, its most likely caused by either the MAF, or the 02 sensors being bad. Also, unplugging the battery would reset the CEL, so you almost need to drive a good distance to see if it will come back on (10-20 miles). MAF's can go bad, and if the problem reoccurs, personally I would start by replacing that. Post back on whether the problem reappears and hopefully more will chime in with their knowledge and experience!

 

[Thermo]

doehunter, if you are getting the P0171 and P0174 codes (both at the same time), I want you to check something. Look on the passenger side valve cover. You will see the PCV valve there. Follow the plastic line that runs off the top of the PCV valve and follow it to where it taps into the back of the intake. Check the rubber boot that is on the end of that tube. I bet you will find that it is cracked and in general, bad repair. Put a new one on and then see what your codes look like then. You are describing a common problem with the 1st gen trucks.

 

[JUST4FUN]

most likely you will fail the inspection with a P1000 code not ready needs more driving time. it might take as much as 3 days and lots of key starts and driving.
the evap system will be the last to come back up