P0401 (EGR flow) after reducing backpressure. Any fixes?

[izak]

I started getting the 401 code after installing JK's exhaust system. From what I've run across on the web, my truck wants backpressure in the exhaust to drive the EGR system. Is there any quick fix to keep it from setting the SES light?

[Dvldog 8793]

Remove the EGR system and reflash the comp for a H.O.(non-egr 6.5) program.
L8r
Conley Janssen

[izak]

I guess that would be the ultimate solution. I am trying to find a donor L65 PCM, just havent found one yet.

Ever since I got the truck back after having the IP replaced it has started bogging down now and then. It will belch out black smoke when I start accelerating. After a few seconds and a ton of smoke it will start to rev up, boost will kick in and then it will take off. It seems to be getting more frequent so it may be related to this "EGR flow" code. I'll try monitoring the vacuum to the EGR valve and see if that looks in order. Maybe I have a hose coming loose.

[izak]

I unplugged the egr valve and ran a vacuum gauge out the top of the hood so I could watch while driving. It gets about 18" of vacuum at idle. It seems to really back off the vacuum if you accelerate or decelerate at low speed. At speed it always seems to have about 18" inches no matter if you are mashing on the pedal or not. I thought it was supposed to shut off egr when accelerating.

It sure drives better without the EGR hose hooked up! Never got the bogged down, spongey pedal, huge plume of black smoke today. Is it REALLY supposed to work this way? I guess I'll take EGR valve off tonight and see if it's broken, but I cant imagine that replacing it would fix anything given the vacuum signals. Maybe the MAF/Baro sensor is bad?

I tell you what, it drives like a completely different truck. I was seriously considering dumping the thing off a cliff. I think I'll redouble my efforts in finding an L65 PCM now.

[Dihrdbowti]

I think that was the code I was getting also but funny thing it was a geographical thing. I made two trips from Reno Nevada to Sothern Cal via Hwy 395. Both times on my way south in Big Pine Ca. just south of Bishop I got the code. First time stock exhaust second time JK's exhaust. Both times I stopped in Bishop for about 20 mins. Big Pine is about a 20 min drive south.