The codes that I need translated are :

KOEO
23
33
41

KOER

23
33
41


I am trying to chase fuel mileage here.

This is an 89 F250 4x4, 5.8, FI, C-6 tranny, 4:10 gears
New ford crate engine (10,000 miles on it)
New exaust (strait pipes with full flow turbo mufflers, no cat)
new O2 sensor
New Throttle position sensor
New Map sensor
New water pump
New Alternator
New Fuel pumps (all 3 )
new fuel pressure regulator
new injectors (OEM Bosch)
K & N Air filter
new plugs
New wires
New cap
New rotor
New oil pressure sender
new thermostat (195 deg)
Emissions stuff removed
new brakes
new ball joints
new tires
Dual batteries (750 cca @ 0 degrees) they are Semi truck batteries
New EGR valve position seneor
New heater core
new Radiator
new passenger fender
new passenger door
Battery Isolator
New nine foot v-blade snow plow
Knapheide utility box (steel)

As you can see I have dumped a ton of time and money into this truck and am currently getting 6 mpg. The first week that I drove it I was getting about 14 MPG. granted this was during the break-in for the new motor and I was very kind to the gas pedal. but once the rings and every thing else settled in I should be getting at least the same mileage if not a hair better. under normal driving.

as I said, I am currently getting 7 MPG with the truck empty, and the front hubs not locked in, and the plow not on the truck

with the truck loaded (Its my work truck) I get 6 Mpg

With the front hubs locked in (transfer case not locked in) I get 4 Mpg

And finally, plowing snow I get 1.635 Mpg

HELP!!!

a translation of the codes and any other suggestions would be greatley appreciated.


Ugly Truck.

 

Code 23 is the throttle positioner signal is out of range Test:Ignition on engine off/ Engine Running
Code 33 EGR valve fault/ not closing properly Test:Engine Running/Continues memory
Code 41 O2 sensor
Hope this helps

 

code 33: EGR valve opening not detected...Code 41: No HEGO switching detected..

 

According to my manual code 33(egr valve not opening properly) is for cars only.
Code 33 for trucks is egr valve not closing properly.
Code 41
Test engine running: HEGO(HO2s) Sensor voltage low/ System lean
Continues Memory: HEGO (HO2s) Sensor signal out of range/ always lean
Continues Memory: No HO2s switching detected

HEGO= Heated Oxygen Sensor or its circuit
These are from the book for my Ford tester. Tester made by Innova electronics.

 

Also remember that with a check eng light the computer goes into open loop "limp" mode and the sendsors are not controlling the engine operation, just a very rich emergency run program, hence the lousy mileage. Clear the codes and drive it to make sure all come back again and then work on lowest code first. Good luck.

 

^ the computer doesn't necessarily go into limp mode every time the check engine light is on. It shouldn't go into full limp home mode unless it loses a major sensor or two, such as throttle position and say MAP for instance. Just losing the O2 sensor signal will keep it from closed loop fuel control, but shouldn't put it into limp mode.

As for the problem test the TPS to see what kind of voltages you get. It should read less than 1V at closed throttle between the green wire and the black wire on the tps, with the key on, engine off. Then gradually open the throttle and watch the voltage - it should smoothly increase until you get to full throttle, where the value should be right around 4.8V. Also, if the EGR valve is stuck open, the engine will idle like poo - really rough and lopey like you have a big cam, which could also cause a decrease in mileage. I'd also check fuel pressure - low fuel pressure can cause the engine to run lean and throw the code. Code 41 can come up if the O2 sensor is not plugged in as well. Verify that the O2 sensor is connected to the computer and that the internal heater in the O2 sensor has the proper connection to 12V and ground. What color are the new injectors?

 

I have fixed the code for the TPS- It was not calibrated when installed.. I recalibrated it and the code dissapeared... one problem fixed..... next I want to the EGR code... I went back to the auto parts store and had them look up the part again just to make sure that I got the correct one when I changed it about a month ago.... the computer list's 2 different ones. the only way to tell which one that I needed was to determine which one came off the truck in the first place.... I stopped by the ford dealer and had them look up what the ford PT# is ... I have the correct one on the truck. So okay, fixing this code is at a dead end for now.

Next I attempted to diagnose the O2 sensor. I do have 12 volts going to the sensor heater, I do have a good ground reading on the pigtail. But I did not have a decent sensor return signal going back to the computer.. If I remember correctly it shoud be between .35 and .55 volts and I was only getting .012 volts..
So I went back to the parts store and swapped the sensor out as defective and installed another new Bosch sensor and then drove the truck for a while to make sure that it was up to sensor operating temp (600 degrees for the O2 sensor) and then ran the self diagnostic test again. I am still getting codes 33(EGR) and 41(HEGO, no sensor switchng detected) any Ideas???

Yes, I unhooked the Batteries and let the computer clear its memory after I did the repairs, and yes, I did check to make sure that there is no blockage in the sensor port that would block the exaust gasses from contacting the tip of the O2 sensor. and finally, Yes, I did check to make sure that all connectors are clean and tight.

 

Not sure what to say about the O2 sensor, but as for the EGR did you replace the position sensor that is mounted on the top of the EGR. That might correct your EGR codes and who knows may be the O2. Its a wierd world, you never know. I beleive the EGR position sensor runs around $30-40. Hope this helps

 

There are a couple pretty good threads on EGR problems here if you search for them. Go to advanced search and put fefarms in the user name box.

 

The O2 sensor is a MAJOR sensor, it's part of the emissions system, and the computer can't adjust the air/fuel mixture properly without the readings. The O2 sensors will indeed make it run in limp mode. I'd be checking the fuel pressure regualtor. Also the computer need the cats to be installed too.. The O2 sensor is right in front of them, and may not be getting heated properly, so they may not be switching... The increase in flow may also be contributing to the LEAN condition it THINKS you are getting... Many people think the cats are useless junk, but they are more problematic off the truck than on.

 

A missing O2 sensor will just keep the computer in open loop - it isn't a big enough problem to cause the computer to go into limp home mode.