Hey everyone, my 1999 2.5L has i think developed a misfire. I was at school and started it, and it was idling rough, so i went out and felt the exhaust pipe, i could hear popping and what sounded like a backfire noise. when i felt the pipe it wasnt smooth, sucked my hand towards it randomly. I popped the hood and the engine was vibrating more than usual, and i could hear a noise that sounded like an old tractor whose intake valve leaks, or a random glug like sound. hard to describe. I drove it home, probably a ten minute drive and parked it, it wasnt shaking like it was, and the exhaust pipe felt like a little sewing machine. the engine code has been there for a while. I have erased it but when i fill my tank it comes back. its a p1401, and on my OBD2 reader it says it could be misfire, DPFE, and some other things i cant remember off the top of my head. I have never checked out the spark plugs so it may be that too. but it has 8 plugs so if one plug went bad it shouldnt cause it to miss terribly, right? Anyone have any ideas

 

Look codes up here: https://therangerstation.com/tech_li...II_codes.shtml

Especially P1xxx codes, if it starts with a 1 that means is Brand specific, in this case FORD specific
So if you "Google" a P1xxx code you will get BMW, GM, Honda, ect.............definitions, and Ford eventually, lol

P0xxx codes are generic, all car makers have to use the same standard definitions, by law, for P0xxx codes

For Ford it means:
P1401 Diff Pressure Feedback EGR Circuit High Input

This usually means the DPFE sensor is bad, they often need to be replace every 8 years or so, depends on climate and other running conditions

But there should be no poor running if its just a DPFE sensor failure

So..................the code may mean the EGR system has a fault
EGR valve is not closing all the way causing engine to run poorly

There are a few test you can do to see if EGR valve is not closing
First test is to start cold engine, then pull off the Vacuum hose from EGR valve, put finger over the end of the hose, there should be NO VACUUM in that hose, if idle gets better then EGR Solenoid is leaking vacuum, replace it

Another test is using a vacuum gauge hooked to the manifold, with engine running at idle you should see 17-21" of vacuum
If down below 10" then EGR valve is open a bit

Another test is using a infra red thermometer
Start cold engine, test temp on upper intake and then test EGR tube, leave it on the tube and watch if temp is rising quickly, that means hot exhaust gases are flowing into the intake causing the poor running

 

Thanks Ron for the reply. I will check the EGR this weekend and see if it does it again. This is the first time its done it so i don't know if or when it'll do it again.

Dad mentioned that maybe a lifter could be to blame? could that cause the "misfire"? they tick something terrible.

I started the truck tonight and it didn't do it. but if it does it again would it be OK to run it until i can resolve it?

and the code ive had for a while and kinda wrote it off and kept an eye on it. It seems like it comes back after i fill my tank. unless its a coincidence. :)

thanks again

 

The CEL(check engine light) will FLASH if a misfire can damage the engine, so if that happens back off the gas pedal so nothing bad happens, then drive slower

No can't see that code, P1401, changing or come up because of fuel levels

EVAP codes are effected by fuel levels some times