shaner86

What are some issues caused by a bad EGR valve?

TrimDrip

my car doesn't have one. it run the same after I took it off.

they can cause detonation but, you probably won't ever hear it

86 5.0L

The EGR valve, is a vacuum controlled valve which allows a specific amount of your exhaust back into the intake manifold. This exhaust mixes with the intake air and actually cools the combustion process. Cooler is always better inside your engine. The exhaust your EGR valve recirculates also prevents the formation of Nitrogen related gases. These are referred to as NOX emissions, and are a common cause for failing emissions testing. Unfortunately, your EGR valve can get stuck, causing NOX gases to build up. You'll know if your EGR valve is stuck or malfunctioning because your car will experience symptoms like rough idle and bucking on accelertaion.

Rough idle and poor acceleration can be caused by a faulty EGR valve.

TrimDrip

I have a new egr valve if you're interested. It stayed on the car for about 100 miles. When I put the supercharger on, I deleted it. pm me if interested. I will let you have it way less than a new one. I think I paid about 150 for it new.

If it is stuck open like posted above, your car is going to run like ****. You can test it though. Somehow get the valve closed. Some egrs you can tap on. Never tried on a mustang. If it closes, and the car idles better, that was the problem. If you to test drive, unplug the vacuum a block it off so it doesn't get stuck open again. If you want to delete it, unplug the electrical connection to it and it will be deleted and not used by the computer.

You may have to take it off to if you can't get it to close. If it is open when you take it off, that is the problem.

Bubba 95SN

86 5.0 got it correct.

shaner86

thanks guys i will pick up a new egr valve next friday should i get a new sensor for it also ?

TrimDrip

Hey dude, I was hammered last night and really didn't even remember posting that. Anyways, if you want to make sure the valve is closed. You can take the sensor off of the top of it and press it down manually. Also, you can take them off and clean them with brake cleaner and an air hose. May save you some cash. A new egr is going to cost you 140 at least. That is if you buy one for a f-150. One for a mustang, especially an original, will be pushing close to 200.

shaner86

thanks i will take it apart and try and clean it

cookcobra

Yep, I can tell you from recent experience with a bad EGR. My '93 Cobra wouldn't pass but it didn't have catalytic converters, so I installed a new catted x-pipe thinking there would be zero problems. I was wrong. It failed, so I replaced the EGR and it basically cut the emissions readings in half! Very easy repair and Borg Warner part was around $85 - no need to go back with Motorcraft, which is significantly higher in cost.