99 has nearly 300k. Was running well until couple weeks ago and got rough with CEL coming on. Originally code P0172 coming up. Replaced plugs and wires, but that did nothing. Started to hear hiss noise when accelerating. Pulled codes again and now have P0172, P0174, P0300, and P0401. Saw DPFE sensor hose was dangling and only one there. Replaced with new hoses, but front hose ruptured almost immediately.

Is this indication that the DPFE sensor may need to be replaced? When I pull vac off top of EGR, truck almost immediately stalls, so that seems to be working. Pretty good pressure coming out of input line into the DPFE...feels like a air nozzle. Is there supposed to be a lot of flow in that line?

Not sure if CAT is clogged up or not...would that affect engine this way too? No O2 sensor codes, so think its okay, but its not new. Was running great like I said previously before all this mess...has appearance of a vac or pressure line issue. Hoping its just the DPFE?

Anyone think this is way to go? Thanks.

Jim in Jax

 

Don't you think 300k is a long life and expect some issues by now?
Your guessing instead of looking up what the codes mean.
The 172/174 codes are due to the noise you hear. There are now air leaks in some rubber fiting at some point on the intake manifold due to 'rot'.
The 300 code is random missfire.
Repair the DPFE hoses, do some maintaince on the EVR, the IAC and clean the throttle body for starters.
Has the plugs been changed in the last 100k?
I think you have been getting your investments worth.
Now it's time for a little TLC.
Good luck.

 

A DPFE hose that "ruptured" is a pretty good indication of a restricted exhaust. Rough running and the rest of the symptoms match up.

I'd have an exhaust shop airflow test the exhaust to see if that's the problem.

 

Confirmed projectSH089 suggestion that ruptured lines between EGR and DPFE is indicator that cat flow is significantly restricted. I had already changed plugs/wires and rubber, but rubber ruptured shortly later and did not fix problem which apparently is restricted flow. Pro at muffler shop said those were original cats (4) on the truck, so with nearly 300k on the road, got my money's worth. Replacing the stock with Flowmasters (heavy metal) instead, so should fix the problem. Bill will be a little over $500 which compared to replacing with stock from Ford is a great deal.

Will post if that did the trick. Pretty confident though since I blew up new hose right after install on the DPFE this morning. Getting the original ford hose parts to replace those two on the DPFE. Should be good to go tonite.