well I finally got around to installing the dynatech supermaxx long tube headers and cats and I'm not sure if I'm happy. My observations:

The truck seems to be idling rougher now...is that normal with long tubes?

Also, it seems to hesitate a bit when I really get on it and may have even backfired once...wtf is up with that?

Does the computer need to adjust for the change or is that only on the intake side?

I don't know what role the 'high flow' cats play in all of the above but if anyone has any thoughts please chime in. I think I will at least change my plugs because I must have banged into them about 10x throughout the install so maybe I damaged something. Probably do the wires too. Anyway, I can definitely feel the power but if my once smooth and comfortable ride is in jeopardy I may have to make some changes.

 

Is it throwing any codes? Definetly change the plugs, its easy to crack the ceramic on them and not even see it. I would think the puter would need some miles to adjust. Let us know how it goes.

 

Try changing the plugs like you said. I've heard of other people having the same problem. Does it feel like you get more power at all rpms?

 

yeah it was throwing a misfire code but that was easily solved when I found a plug wire melted onto a header pipe. Fortunately Dynatech supplies a couple extra plug wires for the two tightest fits so no big deal.

I definitely have more power at all rpms but it can be hard to really open it up around here. I live just outside Philadelphia and it's mostly stop and go. I'll try to really jump on it in the morning on my way to work.

 

sounds good! i cant wait to get headers.

as far as the computer adjusting, it will learn to adjust to pretty much all bolt ons. just takes some time. disconnecting your battery for 20 minutes usually speeds up the learning process.

 

Does it idle rough or it just sounds rougher? I have the Supermaxx as well, and it definetly sounds alot rougher then before, but that was expected - I didnt experience any codes or idling problems tho.

One thing I'm really curious of -- is the passenger side header very close to the frame? The part where all the pipes go straight down by the frame......mine hits every once in a while and I'm wondering if its just mine or if there all kinda close.

 

actually my problem was on the driver's side. The collector and and part of the cross-pipe were almost touching the front drive shaft. I took it over to my regular mechanic and he heated it up and got it squared away. I didn't notice any problems on the passenger side but will keep your experiences in mind 03GMC.