I have a 1999 F250 (Light Duty) with the 5.4L --- K&N, Chip, TB Spacer and Flow Masterl Exhaust.

My Sercice Engine Soon Light Came on last night so I stopped by Auto Zone and they told me the codes were that Bank1 and Bank2 are running lean. Looked for vaccume lines off and found a cracked elbow on a line from the PCV to the side of the Throttle body. Replaced rubber elbow with a very short peice of fuel line.

I started the truck back up and the Service Engine Soon Light is still on. ANY IDEA'S as to why the light is still on. Is there any other thing i should check?

Thank you in advance for you advice on this matter.

Jim

 

You can do one of two things.

1. Recommended: Have patience. The PCM has to go through a couple of drive cycles to clear the code. It will not be instantaneous.

2. Remove negative battery terminal and touch to positive to clear PCM KAM (Kee Alive Memory). This is harmless. There will be no sparks or anything else bad.


Or, I believe that message could also be caused by bad downstream O2 sensors... Do one of the options above (#1 could take 2 or 3 days), then if the code's still there, have it read again.

 

Thank you for the information. it has been helpful.

I am having trouble seeing how BOTH of the O2 Sensors could be bad. I am having lean on Bank 1 and Bank 2 at the same time.

The O2's were my first thought till i found out they were $52.00 each.

If i clear the PCM and the light stays off then i have the problem fixed?????

I thought the light should go out when the problem goes away and the code will stay for 50 cycles (sounded high to me)or untill the PCM is reset.

I just don't want to keep checking stuff and replacing stuff that i don't need to. less money to upgrade engine with if i must spend it on parts.

 

No, the light doesn't go away until the code clears. Another option you could do is go to AZ and have them clear the code for you. Yes, if you clear the PCM and the light stays off, the problem is gone. Have a little patience with it...

 

Will do thanks
patience and i don't know each other very well.

I have had this truck 7 years and this is the 3 problem and it seems easy now that i have found this site..

Thank you very much and I hope to report on the problem being gone very soon.

 

How far are you from Jax?

 

2.5 to 3 hours

On west coast

 

Oh... I'm about 30 min north of Jax, in Ga...

 

These codes are NOT due to faulty O2 sensors. Don't waste your money on unneeded parts.

Find and pull the 5A PCM power fuse for about 15 minutes. That will reset the computer without resetting any accessory devices.

Steve

 

Jsalty, listen to him... He knows his stuff...

 

On the 98 that's fuse #24 Maxi 30amp in the middle - the green one next to the orange.

 

Thank again everyone. I will try the fuse trick as soon as i get up in the morning.

I am also going to replace the PCV for the heck of it (117,000 miles on it)

Like i said before I have had the truck 7 years and only have had 3 problems
1. Tranny went out 21K
2. COP shorted out 34K
3. Enging light wiht the P0171 and P0174 codes.

Not bad and without this site i could have been spening lots of money and time on this simple fix.

 

You do need to keep in mind I posted a 98 distribution box - I know the 99's are different in some ways.

Every truck sold comes with an "Owner's Guide" - That blue or black book in the glove box. All your fuse info is in that little book ..Here's pics of the pages from mine if you don't have one , hopefully there simular -





Steve mentioned the 5 amp PCM fuse . Actually I never tried that one. That would be #20 (in the 98) located in the fuse block under the dash (center row 2nd one up) Either should work.

Good Luck

 

Boxes are different but i pulled the book and got the correct fuse and we will see when i get her back together. Cleaned the TB while i was in the mood.

boy on the 99 thats a pain in the butt to get the throttle body neck off. half of it is under the firewall. IAC is also way under there.


Thanks again everyone. will let ya know if the light goes out when i fire her up.

 

Yeah the trottle body elbow you have to leave that long bollt inside the bodie during removal and the reinstall.

I don't use gaskets - never have on anything above the manifold. I use RTV High Heat Black silicone sealant (it won't leak this way). Black sets up quicker..

If you have a Murrays, you can purchase a good set of pipe cleaners there cheap!! They work great!! - I chuck em up in a cordless drill and clean the ports that way. Any auto supply or Sears will should have them.

Since you have it apart - clean your MAF w/MAF cleaner or brake cleaner - if you have a compressor - blow dry/clean the MAF w/10 lbs compressed air only.. If you haven'y cleaned the MAF in awhile , that can make a big difference in the way she runs.

Deep creep works best on the IAC - it does both cleans and lubes , work the IAC back and forth by hand , make sure it moves freely - Use WD40 if you dont have DeepCreep to lube her up.