I just ripped the factory exhaust off my 1992 f 350 dually's 460 and replaced it with a set of Heddman headers, "x" pipe, dual high flow converters, dual Dynomax super turbos and 2 1/2" pipes. Just got the truck back yesterday from the exhaust shop. At first she was very quiet and saw very little if no difference in power. After about an hour of showing it off to my buddies I noticed a MAJOR difference in both sound and power. Am I going nuts or did it just have to "break in"?

Also, It did stall while idling. My buddy and I were just talking and all of a sudden it loaded up and choked out. The check engine light used come on when coming off the highway and I noticed it came on later that night in my driveway too. I live in Rhode Island and emissions are pretty strict here so I made sure all the emissions crap was kept and re-connected.

Has any of you guys ever did a similar modification?
Has anyone ever ran into troubles after doing them?
Should I be concerned or do I just need to tweak things out a bit?

One last thing, the headers are very noisy both in and out of the cab. It sounds like an exhaust leak, you know, that "tapping" sound. You can't hear it at idle, just when you give it the gas. The exhaust shop said that it wasn't leaking just the sound of the air going through the pipes. Is he blowing smoke up my a..?

Thanks!!

 

Ok, took her out on the highway last night and it seems we got rid of the check engine light problem but guess what... yup got a new problem now. Before when I opened her up on the highway the trans seemed to shut down at 90 mph. Now it does it at 80 mph. So basically I got a big block that doesn't do over 80 mph so if I ever wanted to race a 4 cylinder I'd loose. I'm begining to regret ever doing this exhaust. Instead of making the truck better it's making it weaker than a ford focus......
Open to suggestions.......

 

try reseting your computer,disconnect the neg.battery
cable for ten minites with the head lights on.
reconnect neg. cable and see if that does it.
it may act strange for a while till it figures out what new things you did then it should be fine

 

I have a set up similar to yours in my 79' F350 SC. I am running Hedman Elite ceramic coated headers (just plain junk) and the DynoMax Super Turbos. My truck is very quiet. The most noise I get is from the air flow into my carb. through a K&N filter. Hedman did say their headers tend to lean out the engine. I hate to tell you this, but I think your set up, like mine, is just plain wrong & bad. Probably doing more harm than good. Suggest you go to www.headerdesign.com. I am sure you will learn a lot as I did. It is a fantastic site. Be sure to register so you can run their header design and carb. CFM programs. You will find out how wrong the Hedman headers are & most others out there. By the way, the individual who is responsible for that site has his Phd. and extensive experience. He is not another backyard welder claiming to know everything about headers & exhaust systems. I lost 2 mpg when I put the Hedman's on. I would be happy to talk to you any time. Pls. feel free to call me any time at 425-226-6033 (Seattle area) or e-mail me at DonCLuther(No Email Addresses In Posts!)