How To: Bypass EGR without getting a CEL

[Destroyer000]

this is also something to think about doing in a state where you have emissions testing like ca. Since my stock DPFE went out, i've probably been through 6 or 7. and that's just in 2 years. They don't last very long, and they are expensive. next time i get a new one i'll just hook it up this way and save it from the exhaust heat until it's smog time. this is a really bad design flaw by ford. ugh.

For now i've just gotten used to seeing a CEL on constantly.

ive Never had a problem with the dpfe valve.. i knew a few people who have had the problem. they bought a new one at advanced/autozone and still had the problem.. then they went down to ford and got a oem one and they have been fine since.. maybe you could try a dealer one.

 

[kimcrwbr1]

From what I have been reading the best way to eliminate the egr system is to use a EEC-IV computer that has the maf setup 90+ and add the maf into the intake. In the tech library under MAF conversion it explains the process. You will gain HP and mileage or overall performance. You can use your existing harness and just add the maf harness to the computer connector. Upgrade your injectors and add a VSS if you dont already have one and then dial it in it looks to me like a more viable upgrade but not sure on the implications on passing the visual test for emissions but sure it will pass the sniffer.

 

[Psychopete]

From what I have been reading the best way to eliminate the egr system is to use a EEC-IV computer that has the maf setup 90+ and add the maf into the intake.

Any 88+ 2.9L doesn't have EGR, so it doesn't need to be specifically a '90 MAF computer. That MAF computer is just convenient for some that need a system that copes better to modifications (like a non-computer friendly cam change). But like what was stated - the intentions of the article are for people who don't have the option of easily swapping to a different non-egr computer.

 

[kimcrwbr1]

So your saying the maf conversion wont work for the stock setup. Or is it more a hassle than it`s worth.

 

[Tom Cat]

I think I know why some people are getting the cell light after this mod.
Wouldn’t the vac hose have to hook up to the p2 port on the dpfe sensor?
Up stream of the orifice is presser (the ref on the dpfe); downstream of the orifice is the vac side were the dpfe reeds a vacuum when the egr valve opens, so logic says that is were the egr vac hose would have to hook up on the dpfe.

I will try this mod when the weather and time permits.

Also when the cell is on the computer is in limp mode so gas mileage and performance will suffer.

 

[birdman]

how about a 302 from a sploder. my egr valve is bad and my tube is broken. local part store wants around 150 for the valve and the tube

my 302 i put a plate in behind to block it off, my motor has 450,000kms and it ran perfect. Its been like this for 3yrs now and not a problem since.
But when i priced a new one it was $150 plus the tub which was a nother $100 so too much for me.

 

[Resurrection Ranger]

On OBD-I where a dyno is used to determine emmisions (here in PA anyway) in a pinch when I needed to have the test done because my sticker was about to expire I simply pulled the dash trim off to gain access to the CEL and crumbled up a piece of paper (an ATM reciept to be exact) and stuffed it in there.

NOW.. if your tester is keen (mine is an old man .. he will notice that the CEL does not illuminate upon KOEO as the ECM will test the light when the key is initially turned to the on position. I just figured he wouldn't look.. he didn't

 

[01b3000ds]

Might I suggest

...another method of defeating the EGR system? This has the potential to throw a code:

Connect the manifold vacuum source of the EVR Solenoid to the downstream side of the DPFE sensor. ECU will see greater than expected pressure differential and command the EGR "to close" (or not open/actuate). Easy enough to reverse if there is a code. Might destroy DPFE. You'd know if the EGR valve was open from the vacuum sound at the downstream port of the EGR tube. Upstream would stay in place at the DPFE.

If this is successful and doesn't throw a code, the downstream tube on the EGR tube would need to be capped.

 

[iPandaBar]

I'm a know nothing aspiring gearhead that bought a project ranger. I'm currently swapping in a reman motor and wanted to delete my egr. Everyone is saying don't do this it can cause detonation, blahblahblah. But exactly how different are the motors for a manual vs an automatic transmission? Seems like an odd question but according to my service manual the 1993 2.3 l came with egr on the manual transmission and not on the automatic. If there is no difference in the engines, why aren't all the automatic transmission rangers from this year blown up or pinging?

 

[wildbill23c]

88+ computer swap on the 86-87 2.9Ls is probably the route I would go, since they did not have EGR from the factory.

Really? My 87 Ford Ranger has the EGR system. My 88 Bronco 2 does not though.

 

[wildbill23c]

I'm a know nothing aspiring gearhead that bought a project ranger. I'm currently swapping in a reman motor and wanted to delete my egr. Everyone is saying don't do this it can cause detonation, blahblahblah. But exactly how different are the motors for a manual vs an automatic transmission? Seems like an odd question but according to my service manual the 1993 2.3 l came with egr on the manual transmission and not on the automatic. If there is no difference in the engines, why aren't all the automatic transmission rangers from this year blown up or pinging?

Depends on where the vehicle was originally sold I believe as to the type of emissions stuff on them. If you got the same truck in California it would have also had a SMOG pump on it as well as the EGR system. I don't think it has anything to do with manual VS automatic transmission, the system would be the same regardless and the engine isn't any different between auto or manual either, the computer (ECU) is programmed different, but the engine itself isn't different. Today I ran across 3 2.9L V6 engines at the pick a part, 1 had the EGR system, the other 2 did not...1 was the 1988, another was an 86 and one was an 89.

Depending on the vehicle you got the engine from it may or may not have been equipped or someone already removed it.

I was told if you remove the EGR system by doing a block plate or whatever, the computer still thinks you have EGR, and will cause fuel economy loss as a result of that system no longer functioning...there isn't any power gain at all from not having the EGR valve VS having one. If your EGR valve isn't working, replace it. This is actually one emissions component that doesn't screw your fuel economy LOL.

As for disabling it in the ECU, I doubt that could be done in these old trucks...only thing someone could try would be an ECU from a truck not equipped with the EGR system and I'm not sure what years those were....my 88 Ford Bronco 2 doesn't have the EGR valve and it never had one as the intake isn't setup for one, but my 87 Ford Ranger does have the EGR valve which is causing issues right now on the highway, I believe the valve is bad as I'll go to accelerate while on the highway and I'll start losing power then its like that valve unsticks itself and then the power loss goes away. I think the valve may be getting stuck open and by doing so when I go to accelerate its trying to suck in too much exhaust gasses and its acting like its going to stall.

 

[adsm08]

I'm a know nothing aspiring gearhead that bought a project ranger. I'm currently swapping in a reman motor and wanted to delete my egr. Everyone is saying don't do this it can cause detonation, blahblahblah. But exactly how different are the motors for a manual vs an automatic transmission? Seems like an odd question but according to my service manual the 1993 2.3 l came with egr on the manual transmission and not on the automatic. If there is no difference in the engines, why aren't all the automatic transmission rangers from this year blown up or pinging?

Well, at least you can admit that you don't know what you are doing and that you are still learning. That puts you ahead of most. Now lets see if you can listen to those wiser than you.

There is no good reason to do what you are proposing. It will not help with fuel economy, reliability, or power, and will greatly increase the amount of actual toxic compounds in your exhaust. I don't care if you are subject to emissions testing in your area or not, deleting the EGR system is still adding NOx back into your exhaust, and its the only thing in the exhaust that is actually poisonous.


Reducing detonation is just one happy side effect of EGR, not it's primary purpose. In fact it only helps with detonation under certain conditions. It does appear that only the manual transmission 2.3L Rangers got EGR in 93, but I'm not sure exactly why. It may have been something in the software allowing the manual trans version to run a more aggressive timing curve, which will cause detonation.

t my 87 Ford Ranger does have the EGR valve which is causing issues right now on the highway, I believe the valve is bad as I'll go to accelerate while on the highway and I'll start losing power then its like that valve unsticks itself and then the power loss goes away. I think the valve may be getting stuck open and by doing so when I go to accelerate its trying to suck in too much exhaust gasses and its acting like its going to stall.

If you disconnect the vacuum switch it will disable the EGR valve, and that should allow you to test for the valve sticking.

 

[wildbill23c]

Well, at least you can admit that you don't know what you are doing and that you are still learning. That puts you ahead of most. Now lets see if you can listen to those wiser than you.

There is no good reason to do what you are proposing. It will not help with fuel economy, reliability, or power, and will greatly increase the amount of actual toxic compounds in your exhaust. I don't care if you are subject to emissions testing in your area or not, deleting the EGR system is still adding NOx back into your exhaust, and its the only thing in the exhaust that is actually poisonous.


Reducing detonation is just one happy side effect of EGR, not it's primary purpose. In fact it only helps with detonation under certain conditions. It does appear that only the manual transmission 2.3L Rangers got EGR in 93, but I'm not sure exactly why. It may have been something in the software allowing the manual trans version to run a more aggressive timing curve, which will cause detonation.



If you disconnect the vacuum switch it will disable the EGR valve, and that should allow you to test for the valve sticking.

Vacuum switch is by the throttle linkage with the vacuum line coming off the underside and going to the EGR valve correct? Or is the switch on the passenger fender? I know if the TPS is unplugged it'll run fine all day long...so I don't know if the TPS controls any of the EGR stuff or not, thought it did but not sure.

 

[adsm08]

Vacuum switch is by the throttle linkage with the vacuum line coming off the underside and going to the EGR valve correct? Or is the switch on the passenger fender? I know if the TPS is unplugged it'll run fine all day long...so I don't know if the TPS controls any of the EGR stuff or not, thought it did but not sure.

It's been a while. I think the vacuum switch is over on the fender. It has a red and a green vacuum line going to it. Unplug it electrically so you don't get a vacuum leak.

TPS is an input to the EGR system, but it's also a major input to the PCM for engine management, so that's not a fair test, because it puts everything in limp mode. Unhooking the vacuum switch should only effect the EGR system.

 

[wildbill23c]

It's been a while. I think the vacuum switch is over on the fender. It has a red and a green vacuum line going to it. Unplug it electrically so you don't get a vacuum leak.

TPS is an input to the EGR system, but it's also a major input to the PCM for engine management, so that's not a fair test, because it puts everything in limp mode. Unhooking the vacuum switch should only effect the EGR system.

Ok, I'll disconnect the vacuum switch and give it a test tomorrow. Kind of leaning towards the EGR Valve, and wouldn't be of any surprise, the truck sat for 4 years so I'm dealing with a lot of issues from a vehicle sitting....the timing gasket failed last week and dumped coolant out of the front of the engine, at first I thought the water pump failed, but it was far worse than that, so it now has a whole new timing set, timing gaskets, water pump, etc. LOL. worst thing for a vehicle letting it set like that . Slowly getting things up to par again just a work in progress in between winter, and work, it just takes some time.

The limp mode you are talking about just pretty much bypasses everything doesn't it? As in the EGR doesn't work, it don't shut down the fuel injectors when coasting, etc.? It also effects timing advance and that type of stuff as well correct?