Misfire - EGR - '00 4.0L OHV

[Andy D.]

Hello again,

So, I'm back with another question. Could a broken, open, EGR tube cause my Misfire issues? I assume that the answer is yes, however I have seen many, and I mean many, different answers about the subject in my search, and figure the Explorer Forum should be my final destination.

I am getting a System Too Lean Bank 1 code, and previously had Sys Too Lean Bank 1&2, however the Bank 2 code has disappeared. Could that also be caused by the EGR system? The break or hole in the tube is at the point where it connects to the exhaust.

 

[410Fortune]

hole in the EGR tube can cause some issues with run ability yes
You gotta get the EGR fixed before you can expect a smooth idle and performance

a hole in the exhaust will allow whats called "un metered air" to enter the system, this is any air that enters between the MAS sensor and the 02 sensor that was not accounted for. The 02 sensors will pick up that there is extra oxygen (more then expected) and the computer will add fuel in order to compensate. When adding the fuel does not fix the issue, the lean code comes up.

Banks 1 & 2 lean on a OHV 4.0L are almost always leaks in the intake plenum gasket especially if you have never replaced the intake O rings, however you cannot determine if this is your cause until you fix the egr leak.
You can look for excessive soot buildup around the base of the plastic intake, where it meets the metal fuel rail...leaks here will show because dirt will accumulate

A hole in a EGR tube can sometimes be patched with a weld, or a exhaust patch, or high heat plastic weld material (the last two are considered a temporary fix)

Let is know what you find!! Welcome to EF

 

[Andy D.]

Hey, thanks for the response. I will weld the tube as soon as I possibly can and update from there. I believe the person before me had used the exhaust repair a few times to fix it as well.

 

[410Fortune]

If you weld on the tube in the truck do yourself a huge favor and disco the - batt cable or you can fry the engines computer

 

[96eb96]

If you weld on the tube in the truck do yourself a huge favor and disco the - batt cable or you can fry the engines computer

I had exhaust work on my newer lexus and the guy who welded it said it is a total myth.He never had a single issue with the battery cable connected. As long as the clamp is close. Not saying he is right or wrong, but he does it all day.

 

[Andy D.]

I'll definitely disconnect to be on the safe side. Better safe than sorry.

 

[410Fortune]

Well I had my PCM fried by an exhaust shop....so I disco my - battery cable

it is no MYTH I can assure you of that, it cost me ALOT of $$$$ and ALOT of grief.................. It took almost 3 months to sort out what had happened to my truck and get a replacement PCM,
then I had to go after the exhaust shop to pay for it.... fun fun

I DO however suspect the idiot left my key in the ON position when he did the welding but I cannot be sure of that.

Regardless it takes 2 minutes to remove the - cable

There are so many modules and computers on these modern vehicles, I can tell you when I weld on them (I do alot of welding) I remove the battery cable...I do not want to fry anything and I know IT CAN HAPPEN