Just wondring if someone could point me in the direction of what to check for. Please talk to me like I am 8 years old and an idiot, I am old school and understand the basic engine but this electronic and smog crap drives me batty. Appreciate any help.

 

P1405 = Upstream DPFE sensor hose off or plugged.

The Differential Pressure Feedback Egr (DPFE) senses the pressure difference between the engine intake manafold vacuum & exhaust manafold pressure, across an orifice thats located below the EGR valve, The DPFE sensor then sends the computer an electrical signal, that it uses along with other sensor inputs, to determine what we're asking the engine to do. Then the computer sends an electrical signal to the EGR vacuum switching valve, to control when & how long to have the EGR valve to remain open, to let exhaust gas to be fed back into the engine through the intake manafold. All to help lower combustion chamber temperatures to prevent detionation/knock & thus to lower oxides of nitrogen content in the engines exhaust.

EGR, Exhaust Gas Recirculation, is sorta like making the engine eat some of its own poo!!!! lol
So if this system misbehaves, the engine won't run well.

The P1405 code is for a loose or plugged Upstream line that runs between the DPFE sensor & the Exhaust manafold side of the orifice tube, thats located below the EGR valve. So locate the DPFE sensor & follow its large diameter Upsream line all the way to its orifice tube connection port, below the EGR valve. As this line runs hot, its common for it to be dryrotted & brittle.
If its not disconnected, split, dryrotted & cracked, disconnect it on both ends & try blowing through it to see if its plugged up. If the engine uses oil, its common for the line or inside orifice thats between the two line port connections, to be plugged with carbon.

Edit: Here is a link for what the DPFE sensor looks like, how to test it & where the line connections go to. The Upstream line is the larger of the two on the DPFE sensor itself, which is likely located on the top rear of the intake manafold & this larger diameter (upstream) line goes to the lower connection/exhaust manafold side of the orifice tube port, located underneath the EGR valve.
http://rockledge.home.comcast.net/~r...tage-Test.html

If the line is pugged, clear or replace it.

If the line is clear & ok, fits tight on both ends, not baked out hard, dryrotted, cracked, split, or soft/mushy/loose fit, then remove the EGR valve & look to a clogged feedback orifice in the orifice tube, located underneath the EGR valve, that the two DPFE sensor lines connect to. So to get to & clean the orifice, we must remove the EGR valve.

Let us know how your trouble shoot goes.

 

Hey pawpaw, thanks for the info. It was perfect and you were right on the money, the upstream line was hard and cracked. But as I looked at this thing both lines that come off the DPFE sensor run to oriface connections on the EGR tube. Is this the way it is suppose to be. I just presumed since one said intake side it was suppose to run to intake manifold vacuum. Again I appreciate the help

 

Yes both lines run from the DPFE sensor to the orifice tube below the EGR valve. The larger diameter line is the upstream line, that the trouble code is for. It connects to the exhaust manafold side of the orifice tube & the smaller dia. line connects to the intake manafold side of the orifice tube.
Notice, Both of these lines & their fittings on both ends are different sizes, so we don't connect them up wrong.

Both of those lines get hot down there & bake out, so check both closely.
If they need to be replaced, use the specified rubber tubing, so it'll withstand the heat.

If the problem turns out not to be the lines, be sure to remove the EGR valve (a fun job) & look down into the opening below it, into the orifice tube & make sure it isn't clogged up with carbon. If it is, which is common, clean it out carefully, so as not to open up the orifice diameter, as its calibrated for the DPFE sensor, to measure the difference in pressure between the exhaust & intake manafolds, so that the DPFE feedback signal to the computer isn't corrupt. If that signal is corrupt, the computer gets confused about how much exhaust gas to have the EGR valve feed back for the engine to eat & that'll make it not run right, all a vicious circle!!!!! Don't you just love technology, having our engines eat its own poo!!!!! lol