93 4.0 expo rough idle power loss ((PLEASE HELP))

[Leith]

Replace your MAF

I had the same problem you have and I did everything that you have done so far too. Today I replaced the MAF ( about the only part left to replace ha ha )
It fixed it completely!!!!
Got it at Autozone for $76.00 there is a $60.00 core charge so take your old one with you to avoid that.

 

[Playtyme94]

im sorta having the same issue but with no codes... runs fine when driving but when im at a complete stop, seems to misfire.... anyone have any ideas??

 

[RALLIART15]

So need some help guys, sorry to bring up a dead thread but saves me typing as I have the same issue but add maf to the replaced list.
Current codes
KOER
411 412 538
KOEO
157 172 173 176 177 181 189 332

Only had the truck a week now decided I missed my last one. Been playing with this a bit now and it's driving me nuts. Ran seafoam thru it with no change.
I'm stumped..

 

[SwaintaN]

Current codes
KOER
411 412 538
KOEO
157 172 173 176 177 181 189 332
.

Is this what your looking for?... Clean your Maf with denatured alcohol and replace your o2s, ive always replaced o2s after a seafoam.

411
(R)
Idle speed system not controlling idle properly (generally idle too high) - ISC
412
(R)
Idle speed system not controlling idle properly (generally idle too low) - ISC
538
(R)
System did not receive "goose" test - TESTS

157
(R,M)
Mass Air Flow signal is/was low or grounded - MAF
172
(R,M)
Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
173
(R,M)
Oxygen sensor not switching - system is or was rich - Single, Right or Rear HO2S - Fuel control
176
(M)
Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control
177
(M)
Oxygen sensor not switching - system was rich Left or Front HO2S - Fuel control
181
(M)
Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control
189
(M)
Fuel system was lean at part throttle - Left or Front HO2S - Fuel control
332
(R,M)
EGR did not open/respond during test or if memory code, did not open intermittently - EVR or PFE

 

[RALLIART15]

Appreciate that but I already had the print out of the codes.
MAF is new, O2's are less then two months old as are plugs, cable, coil pack..
I emptied out the cats.. Not to be an illegal driver but pulled the exhuast due to rattling and half the cat fell out so I jammed it all out with a pipe and that helped with the sluggish quite a bit so it was blocked and had back pressure but it is still stupid rich.. the whole reason for a V6 ranger was MPG's over a full size Dodge but this thing is only getting 10mpg

 

[SwaintaN]

i was getting 10 mpgs, had a lot wrong!!! started with i bought cheap o2s, replaced them with appropriate brand, that got a little better.. my cat was fd, replaced it with a magnaflow hi flow cat system, got a little better... cleaned my maf with denatured alcohol got even better, then it all came down to injectors... i was still getting not so good mpg and some bad foot response.. so while my stuff was getting powder coated i threw in new full set of fuel injectors (really good ones to for only 110 all of them). after that i started getting 13 mpg, you gotta remember these exs werent built for mpg

even with all that done i have headers on mine lots of new seals, all synthetic greases/oils but only get 15-18 mpg

 

[RALLIART15]

15-18 is good enough for me but 10 is killing me.
Exhaust is coming soon, I'll check the brand of O2, maf is new, injectors were on the list and a possible ecu.
This thing is just running retardedly rich and I'm not sure why.. can't afford to pour fuel out the tailpipe..

 

[SwaintaN]

i did fpr when i did injectors.. more like i did injectors when i did the fpr... that fpr caused what your describing.. and same codes.. throw on a new fpr and injectors at the same time do a fuel filter.. make a huge difference in mpg! i get 15-18 with being lifted running 33s on a 3.73ls

 

[RALLIART15]

Ok cool I'll put that on the list..
Thanx

 

[Glenn Brittain]

Hi there guys. Not sure if you still have this issue or not but if you have i do belive i have the answer. this is a common problem that these motors have and it caused by the DPFE sensor. (differential pressure feedback sensor) There is an easy way to fix the problem. firstly remove the top cover from the sensor and remove the filter from it. This is normally the cause. leave it open and take it for a spin. if there is a difference then the filter is blocked. I simply cleaned mine in some degreaser and gave it a blow with some compressed air. instant power restore! the function of this is to regulate the vacuum applied to the egr valve. to much vacuum = to much exhust gas getting into the intake. bad idel and loss of power as a result. hope this helps.

 

[Arthur Alewine]

Pressure is fine. Codes are.

KOEO
335
10 not sure what this is
173
336
536

 

[DMCL2023]

Hi there guys. Not sure if you still have this issue or not but if you have i do belive i have the answer. this is a common problem that these motors have and it caused by the DPFE sensor. (differential pressure feedback sensor) There is an easy way to fix the problem. firstly remove the top cover from the sensor and remove the filter from it. This is normally the cause. leave it open and take it for a spin. if there is a difference then the filter is blocked. I simply cleaned mine in some degreaser and gave it a blow with some compressed air. instant power restore! the function of this is to regulate the vacuum applied to the egr valve. to much vacuum = to much exhust gas getting into the intake. bad idel and loss of power as a result. hope this helps.

Hi,
Does the DPFE sensor come apart? Is that the plastic black rectangular object bolted onto the side of the block? I thought it can't come apart. Thanks

 

[Michelle Dandurand]

I believe that they are referring to the EGR solenoid , it's got a round top and is right next to the EGR valve on the upper intake manifold