p0171, p0174, p0401 99 ford E350
 

Hello,

I have a 99 ford E350 with 112K miles, that im trying to chase these trouble codes. i do know that 171, and 174 is lean bank 1 and lean bank 2. i have checked for vacum leaks in/on the hose's, and didnt see anything. also checked the PCV hard line going from the back of the intake to the valve cover, and all looked good. took the air filter off and looked at the MAF sensor. visually it did not look dirty. i have changed out the DPFE sensor, as i found on the internet by changing this this could get rid of 171 and 174 code as well as the 401 code.

i have not taken the EGR valve off yet to see what it looks like inside, but could that be something that would cause these codes.

also the fuel filter has not been changes in a couple of years, the last time it was done was back in 8/04 at 72K miles.

i have reset the code several times, and it seems to come back on around 40 miles later. not sure were too look next.

Mods i did not see a forum for E350's so if im in the wrong place can you move it please.

Thanks,

The full-sized van forum is here:1968 - Present Full Size Vans - Ford Truck Enthusiasts Forums

However, if you can be a little more specific about which engine you have, I can direct you to one of the more engine specific forums where you should be able to get a few more responses.:-X22

powerstroke,

its a 5.4 triton gasoline motor. this is a 15 ft box truck.

thanks,

You may want to look/post in the Modular V8 section found here:
Modular V8 (4.6L, 5.4L) - Ford Truck Enthusiasts Forums

I had a lean bank 1 code on my 99 Expedition ended up being the PCV hoses were rotting away. But it sounds like you've checked that already. Anyway you may have some luck in the V8 forum as this is more of a motor specific issue.

-Torsten

thanks torsten, ill post over there. BTW the PCV hose on this truck is a hard plastic hose.

Pull the pcv elbow off at the manifold end and, really check the rubber elbow closely.
Mine split on the uunder side.

Thanks Torsten.:-X22 I was about to post the same link to the Modular forum and lost internet service.

If its like my Expy though there is some rubber, the elbows and a small length or two. My PCV had a split right at the valve cover with short lengths of rubber hose attatching to the hard plastic.

No problem. Luck of the draw eh? :)

-Torsten