AutumnOrange97

Hi,
I just traded my 1990 Mustang Gt for a 97 Gt. Love the car, but this is my first 4.6 and I'm having an issue with it.

It idles pretty low, at about 600 RPMs, and surges every once in awhile, also if I am down shifting or let off the throttle, it kind of surges when it is still in gear. It has thrown a DPFE code (which I already replaced). The code is now saying DPFE is unplugged but I checked the hoses and they look fine. The guy also told me he did some kind of mod to make it sound cammed (stupid)? It also threw a couple of other codes that I will have to find again and post. Also when it idles this low the battery voltage likes to go crazy sometimes.

I will try to post the other codes it threw soon. Just trying to get this car running good looking into getting a tuner soon.

Thanks

Chris98Gt

Last owner could have made the hole in the iac gasket smaller. Pull the iac off and take a look, that could be messing with the idle.

JeremyB

mine did this and it ended up one of the hoses came off the intake, idled really low and sounded like it was cammed when cold, but was just getting un-metered air into it, throwing codes from the O2s saying it was lean

uberstang1

The dpffe sensor is part of the EGR system, if everything is connected properly my guess would be the egr is bad.

AutumnOrange97

Yeah I already checked the IAC to see if it was blocked off, and also checked all of the intake tubing. When I first bought it i noticed the DPFE was busted in half, so I replaced it, but it still throws the codes. I will try and get the codes checked today and post them.

AutumnOrange97

And yeah I just didnt want to throw another 60 or 70 dollars on an EGR valve if its not bad, I want to be sure

AutumnOrange97

Found out the problem for anybody in the future running into this.... Egr was hooked up backwards to make it sound the way it did, ha

Harriet61

mine did this and it ended up one of the hoses came off the intake,