EGR function question

[hat_man]

Hello everyone.

I know there are numerous threads on here about blocking the EGR valve and the benefits and problems. I have tried to wade through some of them but most of it is technical and over my head. I understand the EGR (exhaust gas recovery) returns some of the exhaust to the intake air to be "re-burned" for better emissions. I read that blocking it off can improve FE (in some vehicles) but will throw codes and can possibly cause long term damage. If I'm on the right track so far then I'll pat myself on the back.

To block or not to block.....that is the question. Whether 'tis nobler in the mod to suffer the pings and CEL's of outrageous FE, or to take arms against a sea of troubles.........

The questions always comes down to these two extremes. Either completely block the EGR or leave it alone. Now, not knowing all the ins and outs of the EGR and vacuum system I do have a question. Would it be possible to partially block the opening for a partial FE increase? Something like a "block off" plate with a smaller diameter opening in it? Wouldn't this allow some exhaust gas back into the system and keep the ECM from throwing a code while still changing the temperature and "mix" of the air in the cylinders?

Maybe it's a silly question. Maybe not. I don't have a clue. It just seems like the extreme end of the EGR spectrum have already been looked at. I wonder if there is a "happy medium". Go ahead and laugh now. I can take it.

[Chrysler kid]

The egr valve only operates in a modern system when the vehicle is not at operating temperature to reduces harmful emissions.

You will noticed no difference in terms of fuel economy without an egr valve

I deleted the egr valve on my camaro because it restricted air flow into the intake manifold, in the ls1 the inlet tube protrudes significantly into the intake manifold. The car is not stock, I have hptuners for aftermarket tuning and I have the knowledge and tools to make sure the car operates correctly and passes emissions testing

Pro:
My camaro's intake manifold and heads are clean as a whistle
No exhaust or intake circulation restrictions

Cons:
Your car will not pass emissions testing
You are now solely in charge of your vehicles maintenance. Any issues that arise even un related will be blamed on your modification
The next owner will have no idea what an egr is or does

Your answer: retain all factory vehicle components unless you perform all of your own maintenance and up keep.

I hate fords, everything on those rangers and explorers was controlled with vacuum lines and tubing. Be happy your ranger is running correctly, don't add to your possible maintenance problems on a daily driver

[oil pan 4]

Do you have a gasoline engine?
If yes, then don't block it.

The only vehicles that appear to benefit are diesels.

The engine temperature sensor reads air temperature between the throttle and air filter. Not inside the intake manifold.

EGR reduction is normally only used on vehicles that left the factory with too much EGR, a desperate OEM attempt at bringing NOx levels down to acceptable levels. Too much EGR will cause vehicles to sputter at part throttle or have a bad spot.
As far as I know no large number of vehicles made after the late 80s or early 90s has had this problem, unless the EGR broke.

[Piwoslaw]

Originally Posted by hat_man

The questions always comes down to these two extremes. Either completely block the EGR or leave it alone.

You can also increase or decrease the flow. But that is for higher level modders.

I'd leave it alone: The impact on emissions will probably be greater than the impact on FE.

[Daox]

Newer gasoline engines use EGR to increase fuel economy. It'll depend which engine you have if its used as just a NOx reducer, or actual FE improver. In either case, I'd keep it.

[user removed]

EGR allows timing to run at greater advance rates.

EGR controls NOX by lowering peak combustion temperatures.

I had the same year Ranger. I left the EGR system alone. I did run injector cleaner and changed the plugs, big pain on the dual plug 2.3 4 cylinder.

Before you consider altering the EGR system, make sure you have all other potential maintenance issues in top notch condition. Without EGR the engine will knock and you will have to retard the timing to get rid of the knocking, which will definitely hurt your mileage.

regards
mech

[Chrysler kid]

Originally Posted by Old Mechanic

EGR allows timing to run at greater advance rates.

EGR controls NOX by lowering peak combustion temperatures.

I had the same year Ranger. I left the EGR system alone. I did run injector cleaner and changed the plugs, big pain on the dual plug 2.3 4 cylinder.

Before you consider altering the EGR system, make sure you have all other potential maintenance issues in top notch condition. Without EGR the engine will knock and you will have to retard the timing to get rid of the knocking, which will definitely hurt your mileage.

regards
mech

8 spark plugs on a four cylinder, I've never had to work On one maybe you could tell me why ford did that

[user removed]

Ford, Nissan, Mercedes. Twin plugs go back a very long way, before WW2. Very common on aircraft engines.
The reasons can vary greatly. In most modern applications it's emissions. In aircraft a backup ignition system would be a reason with a magneto to provide an ignition in the event of catastrpohic electrical system failure.
In racing applications, better power and or economy.

reagrds
mech

[Chrysler kid]

Originally Posted by Old Mechanic

Ford, Nissan, Mercedes. Twin plugs go back a very long way, before WW2. Very common on aircraft engines.
The reasons can vary greatly. In most modern applications it's emissions. In aircraft a backup ignition system would be a reason with a magneto to provide an ignition in the event of catastrpohic electrical system failure.
In racing applications, better power and or economy.

reagrds
mech

Thanks for the knowledge, my wrenching started in 2004 so there are a few gaps in my mechanic knowledge as most cars on the road are at most 10 years old these days

[hat_man]

Thanks everyone. I was never planning on making any changes. I just wanted to learn more. When I see a situation where only the two ends of the spectrum are considered I always wonder if there is a middle ground. Looks like there isn't any here. I guess I was hoping that if there was, it might help someone else more than it would have ever helped me.