DP question....

[rubberman]

I bought a flex so my local muff shop could do me a 3" DP. well after recieving the flex, its gonna be too long to fit in normal spot on the DP. So me and muffler man was thinking about making a long piece from top flange back to the resonator, elminating the cat and ubend delete. then putting the flex after the last bend. check out pic. any harm in doing this? the gray box is where we would put the flex.
http://www.badongo.com/pic.php?file=...11-11_dp22.JPG

[GTP Dad]

No real harm unless you intend to drive it on the street. A car with no cat will not pass emissions testing and it is illegal to remove one except for racing purposes. You will also have to put an O2 sim on the car or you will get a CEL for cat efficiency. You may want to remove the resonator and move the cat further back. Will accomplish the same thing and keep you legal.

[rubberman]

how about the flex? meaning by putting it where the stock cat would be

[GTP Dad]

Not a real problem putting it there. The aftermarket MagnaFlow high flow cat is several inches shorter than the stock one so you should be able to use the flex pipe along the cat without running into any interference issues. The flex pipe should be stiff enough to keep the pipe from moving too much. Since you already deleted the U-bent you should have a pretty straight shot to the mufflers.

[rubberman]

he mentioned running 3" pipe all the way to the Y. Deleting the cat and resonator. I told him i didnt want to remove the resonator since i heard people talk about drone. But im not gonna go that route. I think 3" to the resonator.

others say that putting the flex where the stock cat was wouldnt work. I dont see why not. the engine doesnt move that much. THe engine still would move even with the flex in the cat location.

[GTP Dad]

I have to agree. I just put TOG headers on my GTP and it is on the downpipe but I see no reason that it wouldn't work the way you suggest. I put a high flow cat followed by a pipe with an O2 sensor bung and then used a glass pack for a resonator. All this is 3 inch and I intend to split it into 2-2.5 inch pipes to go to the mufflers. This should give me good sound and scavange gasses very well. The open glass pack sounds great.