EGR delete? Is it worth it? 03 4.2L manual
Thread Starter
Junior Member
Joined: Aug 2021
Posts: 15
Likes: 1
From: East Texas
While the exhaust going back into the cylinder is hot, for the purpose of the chemical reaction that occurs during combustion, it's inert. So it might be a little counterintuitive to learn that the purpose of EGR is to reduce combustion chamber temperature but it's a fact. It can lower combustion chamber temps by as much as 300*F.
The link you provided was a diesel-centric site. While EGR does perform the same function on a diesel- lowering combustion temps to reduce NOx, EGR can cause some pretty serious issues on a diesel that don't occur with gas-burners. I like EGR on a diesel but I've had some serious port cloggage before due to an injection problem that resulted in super-sooty EGR flow. Anyway, I can *almost* see removing a primitive EGR system on a primitive diesel motor but no way no how on a gas burner with electronic engine controls.
The link you provided was a diesel-centric site. While EGR does perform the same function on a diesel- lowering combustion temps to reduce NOx, EGR can cause some pretty serious issues on a diesel that don't occur with gas-burners. I like EGR on a diesel but I've had some serious port cloggage before due to an injection problem that resulted in super-sooty EGR flow. Anyway, I can *almost* see removing a primitive EGR system on a primitive diesel motor but no way no how on a gas burner with electronic engine controls.
You've all been very helpful. And you'll be glad to know that I have put to rest the idea of deleting my EGR.
But while I have the attention of such knowledgeable people, maybe you could help me out with a little problem that I have. The one that originally led me to suspect it was the EGR...
Every morning when I go out and start my truck and take off down the road it's very responsive. Then as the engine warms up to standard operating temperatures it seems to lose that responsiveness. Any thoughts?
Senior Member
Joined: Nov 2017
Posts: 6,637
Likes: 1,292
From: Washington
EGR Removal
There are two ways of removing the EGR System from the vehicle. The first way is by using one of our EGR Delete Race Pipe Kits, these can be found on our website here: https://www.darksidedevelopments.co....ves-and-parts/
Senior Member
Joined: Jan 2021
Posts: 528
Likes: 222
Could be a lot of stuff. For one, the hotter the engine, the more heat added to the intake air as it makes its way into the combustion chamber. This reduces density and power follows. There's also a ton of modifiers for spark timing in the PCM. Some for intake air temps, some for coolant temps. You aren't the first person in The South to talk about disappointing engine performance in August.
5 Year Member
Joined: Apr 2014
Posts: 1,708
Likes: 251
From: St. Petersburg, Fl
Back in carburetor days the smog pump EGR chocked an engine way down and deleting those help a lot not so much on newer engines. A good scanner that can read live data and pending codes will help diagnosing your issue. A Bluetooth Elm327 OBDII adaptor and Torque app on an Android phone or tablet is a cheap way to do that.
Thread Starter
Junior Member
Joined: Aug 2021
Posts: 15
Likes: 1
From: East Texas
Google is for making money. A place to sell stuff. Like EGR Delete Race Pipe Kits.
EGR Removal
There are two ways of removing the EGR System from the vehicle. The first way is by using one of our EGR Delete Race Pipe Kits, these can be found on our website here: https://www.darksidedevelopments.co....ves-and-parts/
EGR Removal
There are two ways of removing the EGR System from the vehicle. The first way is by using one of our EGR Delete Race Pipe Kits, these can be found on our website here: https://www.darksidedevelopments.co....ves-and-parts/
Thread Starter
Junior Member
Joined: Aug 2021
Posts: 15
Likes: 1
From: East Texas
Could be a lot of stuff. For one, the hotter the engine, the more heat added to the intake air as it makes its way into the combustion chamber. This reduces density and power follows. There's also a ton of modifiers for spark timing in the PCM. Some for intake air temps, some for coolant temps. You aren't the first person in The South to talk about disappointing engine performance in August.
Is it not adding more hot, less dense, and polluted air into the intake?
Senior Member
Joined: Jan 2021
Posts: 528
Likes: 222
Well when you say "responsive", I assume that you mean a transition from lower loads to higher loads. EGR would be shut off when TP rate exceeds a threshold. So when you push the pedal down, no egr. There are a huge number of checks in the PCM on egr operation. It pretty much only works when you can't notice a change in engine output, like during cruise. But don't take my word for it, pull the vacuum hose off the EGR valve and see if it fixes your problem.
Thread Starter
Junior Member
Joined: Aug 2021
Posts: 15
Likes: 1
From: East Texas
Back in carburetor days the smog pump EGR chocked an engine way down and deleting those help a lot not so much on newer engines. A good scanner that can read live data and pending codes will help diagnosing your issue. A Bluetooth Elm327 OBDII adaptor and Torque app on an Android phone or tablet is a cheap way to do that.
thanks!
Thread Starter
Junior Member
Joined: Aug 2021
Posts: 15
Likes: 1
From: East Texas
Well when you say "responsive", I assume that you mean a transition from lower loads to higher loads. EGR would be shut off when TP rate exceeds a threshold. So when you push the pedal down, no egr. There are a huge number of checks in the PCM on egr operation. It pretty much only works when you can't notice a change in engine output, like during cruise. But don't take my word for it, pull the vacuum hose off the EGR valve and see if it fixes your problem.
Senior Member
Joined: Jan 2021
Posts: 528
Likes: 222
Trust but verify. I think you should try unplugging it. It won't hurt anything other than send you to hell for making some extra NOx.
The 6 cylinders have an EGR port for each cylinder. Sometimes one or 2 get clogged. The total mass of EGR sent into the engine does not change since any reduction in measured EGR flow only results in the PCM opening up the EGR even more. So those 4 ports get some extra flow causing problems and the 2 without flow are doing great. It's not super common but it can happen and has been a problem on earlier variants of this engine.
The 6 cylinders have an EGR port for each cylinder. Sometimes one or 2 get clogged. The total mass of EGR sent into the engine does not change since any reduction in measured EGR flow only results in the PCM opening up the EGR even more. So those 4 ports get some extra flow causing problems and the 2 without flow are doing great. It's not super common but it can happen and has been a problem on earlier variants of this engine.
