Code 335 1994 Exploder
 

Need Help/Advice.

Yesterday cleared all the codes and restarted.

The KOEO tests all reported no faults.
The KOER tests all reported no faults.

Some of the comments found say that it is a KOEO fault but none reported.

:-X19Today I drove about a mile and the engine was fully warmed up. The check engine light came on and shortly thereafter went off.

I returned to the house and ran the KOEO test again and sure enough the Code 335 was reported.

I am using the INNOVA Ford Code Reader.

I am inclined to think that it is the EGR Valve however based on comments herein, it could be another item/items.

Would like recommendations.

:-huhBy the way, the only symptoms that could be related is the slow acceleration/low power. This kind of leads me to the EGR Valve.

I need to drive car from Sacramento to Fallon NV this Thursday or Friday. Any help will be appreciated.

Thanks.

A KOEO 335 is set with the engine off, and the movement of the EGR valve isn't applicable. KOEO codes are almost always electrical in nature -- in this cases it points to a fault in the DPFE sensor circuit. Either there's a fault in the wiring between the PCM and the DPFE, or the DPFE itself has failed. As frequently as the DPFE's fail on these, I'd check the wiring and, if it checks out, replace the DPFE.

I have changed the egr valve and the retanguler sensor directly below the egr valve three times. I am assuming the retangular sensor with the two vacuum lines on the bottom (1 larger than the other) and the grey plug is the correct item.

I am also assuming that the PCM is the computer inside the cab under the passenger kick panel.

With both being correct, if I am, then what do you recommend is the best method for checking the wires and which ones? Continuity, visually, or some oher method.

I am so tired at this point I can't even think. I am still pursuing the issue but at my age, I need to take a rest.

Another question: I have driven the vehicle twice today and the last time, around 1/2 hour, the CL came on 5 times and after a few seconds went out. Since it is a soft fault, what is your opinion on driving it 175 miles? I just changed the tranny and the last thing I want to do is damage it.

Thanks in advance.

Those are not vacuum line but silicon exhaust tubes, inside the exhaust manifold is a baffle and those tubes send exhaust to the DPFE which senses the differential pressure.

Make sure those hoses are secure/tight, no leaks and that there is pressure coming out of the manifold.. NOT plugged..... Philip

Not sure we are talking about the same thing. Can you refer me to a picture? Thanks

The DPFE looks the same however, My vehicle 4.0 California has a EGR Selonoid. The lines you spoke of earlier connect there.

Now I am beginning to think that the EGR Selonoid is bad.

I don't have the hook-up in front of me and it is late here. I do know that the connection to the front of the EGR Valve (Mushroom Head) goes to the Selonoid. I think the other line from the Selonoid goes to the manifold. One of the vacuum lines from the DPFE go to the Exhaust tube from the Bottom of the EGR Valve. The other line from the DPFE connects to the selonoid. The electrical connection from the Selonoid connects to the intake manifold as I remember.

Not sure which component is causing the code 335 and CEL but since I have replaced the EGR Valve and changed the DPFE 3 times, I am guessing the EGR Selonoid is bad.

Bear in mind, I only get the 335 when the vehicle is moving down the road. Although it is a KOEO code, which I don't get, I only get it KOER and driving.

What is your opinion?

Maybe your DPFE sensor and solenoid lines are misrouted. As mentioned by Aquanaut, the lines to the DPFE should both go to the exhaust manifold. There is an orifice in the tube from the exhaust and one line should go to each side of the orifice. The DPFE then looks at the differential pressure across the orifice and determines EGR flow. If only one line goes to the manifold and the other to the solenoid, that DPFE is never going to get the correct reading.

The electrical connector for the solenoid will not go to the manifold, but may go to a wiring harness near the manifold. Generally the connectors are keyed so that they won't plug in to the wrong item within reach (limited by the wire harness and wire length) so I wouldn't be too concerned about being electrically connected incorrectly.

-Rod

I'm not worried about the electrical side. I'm going to look at a few cars today and double check the routing. One I've made a comparison I will solve that however, I am still concerned about the EGR selonoid.

I am sure you have a routing issue, the EGR should be closed at idle and slow speed, only opening once you are cruising.....Philip

OK, here goes.

The two vacuum lines from the DPFE go to the exhaust tube from egr to manifold. The front connection goes to the upper connection on the tube. The inner line goes to the back connection goes to the lower connection on the tube.

The inner line on the EGR selonoid go to the EGR valve. The outer line goes to the opposite side of the engine and ties to many auxillary components.

The electrical lead to the DPFE is correct.

The electrical lead from the EGR selonoid goes to another component on the top of the engine. There is a silver colored cylindrical unit that is mounted on the side. What is this item called and will it affect the EGR.

Now for some additional information. I checked the codes this morning and the 335 was gone however, I found a 172 & 176 code.

I also had some hesitation last night and at one point the engine almost stalled. It also felt temporarily like it was running out of gas.

Another thing that I found is when the ignition is turned on that sometimes the fuel pump does not immediately come on. It some takes a couple of off/on's to get it to motorize. I am thinking the fuel pump relay. Is it in the power distribution Box?? or, possibly the fuel pump giving signs of failure??

Still wondering about the EGR Selonoid??

It seems like the further I go, the behinder I get. :-X19

What do you suggest now? I have cleared all the codes and ready to redo the KOEO and KOER but waiting for further input so I don't have the same problems.

Need to get car smogged tomorrow if possible. California is a pain sometimes. The car is ultimately going to Fallon, NV where SMOG is not required.

Based on the codes found, etc. is it safe to drive to Fallon at this point. I don't want to have problems over the Sierra's. If not recommended, I will try to take next week if all issues are not resolved today and tomorrow.

This unit is the AIC, it regulates the idle...

The 172 indicates an air leak (lean), and
the 176 is the O2 sensor reporting lean
Both indicating an illegal air leak somewhere...

vacuum line off or mis routed... connect a vacuum gauge to the distribution T...
should read 19-21, with a steady needle...... at idle.. Philip

OK, car running now at idle. Vacuum has minor fluctuation between 20 & 20.4. Is this acceptable or should I did deeper.

That reading is OK, the quiver is probably a sticky valve..or bad PCV... Philip

I just drove the car again and: Code 172 and 176. I can't find or hear any leaks. Maybe signs of my age. Besides a vacuum leak, is there anything else that will cause these codes?

Looks like that is all I have to find except for the 543 code. I only get this when I turn the key on and the pump does not kick on. I think it is the relay which I will replace tomorrow. Could this also be something else?