i just pulled the codes off my 89 f150 5.8L. the engine was JUST rebuilt but it's throwing codes 33 (insufficient EGR FLOW) and code 41 (EGO not switching (bank 1)) those are both KOEO. an input on this

 

The EGR code could be a stuck valve, or a missing/broken/cracked vacuum line. Or the EVP sensor might have a bad connection or be bad itself. The other could be a dead HEGO sensor, or a clipped wire somewhere, or a bad ECM.

Jason

 

i JUST had the engine replaced, prior to having the engine replaced it ran fine. so i'm hoping its a disconnected vacuum line.

 

wheres the egr valve and teh evp sensor located on the 5.8L?

 

If its like my 5.0 it is bolted to the upper intake manifold, pasenger side and there is a steel tube on the bottom that goes to the lower intake area. The electrical sensor(evp) is on top of the egr which is held on with 3 scews and has a vacuum line attatched to it.

 

EGR/EVP are in the same place on both the 5.0L and 5.8L truck engines.

Jason

 

I hope this helps, my truck ran fine accept for stalling every so often and sometimes it would run fine fore a month and not die when i got help on taking the egr off it was rusted in closed pos i took a 1/4 nut driver and taped it once wit a hammer spreyed pb blaster cleaned it out hasnt died since, of course this is tempory fix cuz at one point or another it will happen again i checked local napa cost about 132$ tax included good luck.

 

can someone take a picture of teh location of teh EGR valve? i still can't find it. thanks

keith

 

I can take a picture later today .

 

Look at the passenger's side exhaust manifold. There should be a pipe that comes off it toward the front of the engine, about 1" in diameter. On top of that pipe is the EGR valve. On top of that is the EVP (controls the EGR valve with vacuum and an electrical device/sensor). The whole assembly is also connected to the throttle body.

Jason

 

I have posted a picture of a spare egr valve that I have and a shop drawing in my gallery. Hope this helps you find it.

 

egr is fine. not clogged up or stuck. gotta test the evp sensor tomorrow.

 

I have replaced a couple over the years.

 

replaced a couple... egr valves or evp sensors? also where and what is the EGO (HEGO) sensor. sorry dunno which it is. my code reader said EGO and someone above said HEGO.

thanks

keith

 

I have replaced the egr complete with the sensor on top as I was not able to purchase separately. I have also replaced two of the egr regulators which control the flow of vacuum to the egr valve to either open or close it. The regulator is controlled by the computer. Keep in mind that it is two regulators and two egr valves in 18 years for me. There is a lot of things that can go wrong to the egr system. You have electrical, vacuum, vacuum lines, wiring to the egr and computer ,sticky egr valve from deposits,defective sensor on top of egr. If you go thru the system step by step and do your checks you can find out which is the piece that is giving you the trouble. I have 4 manuals for my vehicle.Some of these things you can figure on your own but you need at least one manual for values that you are looking for and to help you understand how things work. HEGO means heated exhaust gas oxygen .I am not 100% sure but I think the sensor has a electrical heater built into it to help it warm up faster so it can start sending signals to the computer.And ego would be a sensor without the heater I would assume. I think people are talking about the same thing ,your oxygen sensor. I would repair your egr system 1st then see if you still get a code for the oxygen sensor.