So my loving mother bought me a truck to use for various household hauling. I drove it about 200 miles and now I have many trouble code issues that have been detected. p1401, p0761, p0401, p0402. I understand that 2 of the issues are related to the EGR valve. The check engine light came on and the o/d off light was blinking. My question is do i have 2 different issues going on ( one with emissions and one with transmission) or am I missing a post about some weird ford issue that is an easy fix?

 

Welcome to FTE.

Lucky you that Mom bought you a vintage set of wheels. It may just need some light repairs & the past & present due scheduled maintenance brought up to date, a little more trouble shooting will tell.

Good idea to have had the computer scanned for trouble codes & posting All of the Numbers, as they can offer up good trouble shooting clues. Yes your right about having two seperate problems, one with EGR feedback & the other with the tranny.

P0401 = EGR flow insufficient, P0402 = EGR flow excessive.
P1401 = DPFE sensor circuit high voltage.

So it seems that the EGR system is working, but is not in control of EGR flow for some reason & the DPFE sensor & its connecting hoses have earned the right to be high up on your suspect list.

So check the condition of the rubber hoses running from the DPFE sensor, down to the fittings below the EGR valve. If they're ok, not dryrotted/cracked/loose fitting, nor the one coming from the exhaust manafold fitting is plugged up with carbon, then check that the vacuum line to the EGR valve control diaphragm is in good condition & fitting tight & that its run back to the vacuum switching valve that the computer uses to send control vacuum to the EGR valve diaphragm, is in good shape & its fitting tight at the vsv.

If that looks ok, at idle you shouldn't have any vacuum on that line, if you do, suspect the vsv is sticking open, or its diaphragm inside is leaking vacuum, so put it on your suspect replacement list. It can be crudely tested with a blow back test, if you can easily blow back through the EGR vacuum line fitting, the vsv is likely bad.

If the vsv & its vacuum line to the EGR check out ok, then apply vacuum to the EGR diaphragm & see if its holding vacuum ok. If it is, then with the engine at idle & you apply vacuum to the EGR diaphragm, to cause it to open, the engine should idle rough, or maybe stall. If you can quickly apply & release vacuum & the idle will recover, the EGR diaphragm & valve are likely ok & the EGR isn't likely sticking open from carbon deposits.

SO, if all that checks out ok, that leaves you looking at the DPFE sensor, so either test, or replace it & let us know how it goes.

Seeing as how you seem to like turning your own wrenches, there are EGR system links in the "Tech Info" thread atop this forums thread index page, so be sure to check them out too.

The P0761 = Tranny shift solenoid C performance, or stuck off. If the tranny fluid looks to be dark/oxidized/smells burned, maybe consider a tranny pan drop, fliter change & full fluid flush, following the flush routine in the link at the bottom of the Tech Info thread here https://www.ford-trucks.com/forums/6...-pump-out.html would have the new fluids detergents tidy things up enough to unstick the solenoid.

Some thoughts for consideration, let us know how your trouble shoot goes.

 

Thanks for the help! Finally got around to doing the transmission flush and think I found the main issue. 12 out of the 18 bolts I removed by hand. After dropping the pan and replacing the filter I tightened all the bolts down tight and problem fixed. Shifts through all gears and the o/d is actually working now. SMH, I changed the gas cap too, now to just reset the codes and run it again.

 

OK, good feedback & to hear you got positive results with the tranny fluid service. If you'll remove the battery B- cable then switch on lights, or open a door so it'll switch the overhead lights load on, it'll discharge the computers KAM quicker & erase the trouble codes. Removing the B- cable will also wipe the fuel trim tables & the cold & warm idle strategy. So, switch off the electrical load, reconnect the battery B- cable & with the engine cold, perform the cold & warm idle relearn strategy routine, to prevent possible driveability problems.

A tranny service won't likely affect the EGR problems, so don't be surprised if those codes return. Keep us posted on how it goes.