I Just Joined Your Site And Just Purchased A 01 3.8 V6 This Month. The Day After, I Had My Service Engine Soon Lite Come On. I Had It Scanned With The Obd2 And It Came Up As P0401 Egr-insufficient Flow. The Dealer I Got It From Jerked Around With It For Several Days Off And On Claiming They Fixed It But The Lite Continued.
One Week Later I Had Dual Exahuast With Flowmaster 40s Installed. The Same Lite With The Same Code As Above Still Continues. The Egr Valave Has Been Replaced. The Stang Runs Fine And Sounds Fantastic.
Anyone Have This Experince And Have Any Ideas On How To Get This Lite Off? Reprogram Computer? Add H Pipe For Back Pressure? Replace Egr Intake Switch/selenoid?
From Some Reviews I Have Seen On This Site You Guys Have Some Great Stuff In Here And I Hope You Can Provide Some Excellent Advice On My Case Asap. Thanx.

 

An SCT tuner will help for sure, you should be ableto read and clear that code...and on top of that you'll get a nice performance boost, both power and gas mileage

 

they cost around 350 range
here is a link of some tuners for your app
http://americanmuscle.com/99-04-must...ps-tuners.html
http://rpmoutlet.com/musv6mag.htm

 

I had a cat back one into two dual exhaust originally installed but had clearance problems getting around the Ford stock fuel line and filter tucked up underneath the right rear wheel/axle well. So we decided to re-route and go straight duals from cats to rear. I fear the back pressure changes has caused my above EGR complaint.

Doesnt ANYONE on this site know about this? I am disappopinted your so called senior experienced personnel have not replied.

 

most of us are young and dont have years of experience. so we do the best we can. when helping.

 

alot of times when you add highflow exhaust it will toss EGR codes because it either gets to much or not enough exhaust gas flow into as it did stock. It isnt a problem and a simple tune will turn it off and you wont have to worry about it.

 

What does this mean? A simple tue up? ie repacing the plugs? thats about all you can do on these newer vehicles. I dont think that will remedy my problem. Isnt there anybody out there who knows about this?

 

spike, does this happen with the GTs too? im actually having the same problem as this guy at the moment. getting p0401 (EGR Flow insufficient), replaced the EGR valve and still gettin the code. What needs to be tuned in order to get everything resolved?

 

he means a tune like a dyno tune or a flash tuner like in the link i posted above

 

YOu need to get a tune aka a tuner or chip that reprograms the ecu. Like i said alot of times when you mess with exhuast flow you will anger the EGR system as it will either get to much or not enough exhaust gas. A tuner can go in and turn off the light for the egr or turn it off for you. Justin at www.vmptuning.com can help you with that and you will get more power also which is nice.

Its just a simple matter of exhaust gas flow. The stock ecu isnt setup for highflow exhuast systems thus the code for egr. Also replaceing the egr in these situations does nothing for it.

 

With THAT attitude you're lucky anyone answered you at all. Maybe try being more polite next time?

 

well dont quote me on this but it is not uncommon for our 99-04 v6's to get exhaust manifold leaks. This is do to water from the AC dripping on the header and making it crack causing a leak. This may be why you have the code insufficient flow. It could be leaking form the header before the sensors. Something to take into consideration, or if nothing else a place to start your searching.

 

that was a problem i had. $150 fix drivers side header should have just got new ones

 

****, we thought we saw something leaking when we were doing seafoam on my car a few weeks back, weren't too sure as it was getting a bit dark. i guess we'll get under the car this weekend and check it out.

 

Polite or not, two of the above replies are more of what I was looking for. I hope the dyno tune will ensure an increase my gas milage (which by the way sucks due to this) and, will actually CORRECT the situation and not just clear the codes. I can do that with the OBD2 I bought.
Also the exhaust manifold leak potential is great to know as my EGR valve feeds off of the right bank exhaust manifold just near the AC condenser. I will investigate both of these.
Will changning the O2 sensors and/or Air Injection Sensor make any difference? I also have a K+N air intake sytsem on. Or, what aobut the EGR induction switch/selenoid that is vacuum hosed to the EGR?
Thanks.

 

like i siad replacing anything wont fix this thats not the problem. Stop throwing money at it. its from a lack of "flow" think about it replacing random sensors wont fix this. Do you have stock exhaust manifolds or do you have aftermarket headers on your car by the way?

 

maybe this will help. i found these while looking for something else and thought they may remedy the problem.:

MIL Eliminators 1996+ Mustang and All FordsAvailable for all 1996-2004 Dual Exhaust Mustangs and 1999+ Lightning's.
MIL Eliminators or Malfunction Indicator Light Eliminators, are electronic modules that prevent the "Check Engine" or "Service Engine Soon" light from coming on when an offroad H or X pipe is installed on a late-model vehicle with OBD-II emissions systems. If an Offroad H or X pipe is installed on the vehicle without MIL Eliminators, the "Check Engine" or Service Engine Soon" will always be on, and the driver won't have the opportunity of being alerted if something more serious is wrong with the vehicle.
Works with ALL brands of Offroad and High-flow H and X pipes including but not limited to: Bassani, BBK, Dr. Gas, MAC, VRS, Magnaflow, YODUDE and SHM.
2 MIL Eliminators with wiring (one for each rear O2 sensor) included.
Easy to follow, detailed instructions with photos and diagrams.
MIL Eliminators install (Splice In) between the O2 sensor connector and 02 sensor on EACH REAR O2 SENSOR of your vehicle. Installation takes about 30 minutes with basic hand tools.
1 Year Warranty.

i found them on this site
http://v6mustangstuff.com/engine.htm

post and let me know if this helps you or not.

 

those are to turn off the check engine light when you dont run cats. that isnt the problem he has an EGR problem. A tune will turn off the EGR valve and seal it and they will turn that whole system off for him. Or if it is leaking at the manifold that would be the problem also.