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post #1 of 5 (permalink) Old 09-22-2008, 09:08 PM Thread Starter
Join Date: Jul 2008
Posts: 14
almost finished my exhaust, manifolds next!

so i just about got my exhaust done, dynomax ultra flow welded muffler, stock tail left on, not worried about that, today i got around to taking my catalytic converters out, only had 3 to take out so it wasn't too much work, 1 straight pipe welded in place, another with a 45 degree bend and welded in place... just got the damn leaky manifolds with broken studs left! ****!! hate them cuz these ones are pretty burried in the fender well to get at,

but i've noticed with the cats out, it almost feels like i've lost some torque at take off, but have a bit of a gain once i hit higher rpm's, does that sound right? i used to barely need to touch the gas to hear the tires squeal a bit, but now i gotta hit the peddle to the floor to feel the power, but once i get going i can feel the power almost like a power boost around 2500 - 3500rpm's. seems kind of odd i thought i woulda gained more torque at take off without the cats in there

especially since the left side one was all melted and probably not working as well as it should have, i'm thinking the computer might have been reprogramed in some ways cuz my check engine light hasn't come on yet and in my guess should have came on with the left side only having half of 1 cat which was melted in there
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post #2 of 5 (permalink) Old 09-22-2008, 09:18 PM
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Location: Waterford
Posts: 3,019
you dont "lose" hp it just moves your power band around so rather then low end you now have more highend power it also can change the backpresure enough to throw some codes....

toss some freeflow cats on there at least help the environment a littlebit lol
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post #3 of 5 (permalink) Old 09-23-2008, 12:54 AM
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Location: London, ON
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maybe disconnect the neg. batt. terminal for about 15 mins. this should clear the adaptive memory so the truck has to relearn the current settings.

Whaddya mean I dont pay my bills?? Whydya think I'm broke!!

03 Lariat Crew 4x4 Line-x bedliner, Truxedo Lo-Pro QT Tonneau.
RIP [97 XL 4.2L V6]
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post #4 of 5 (permalink) Old 09-23-2008, 08:11 AM
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Location: Elliot Lake, Ontario
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When I put the long tubes in with the high flow cats I didn't notice much gain in the low end but when I hammer it doing about 60km's she snaps you back now. my mid range, and passing gear improved allot, I did gain a little low end.

I only drive in the city, to get out of it!!!
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post #5 of 5 (permalink) Old 09-24-2008, 01:55 AM
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Location: saskatoon SK
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taking the cats out you loose bottom end, but you gain it in the higher rpm's, thats why i havn't cut mine yet, i like the bottom end especially for offroading. i tried the dynomax ultra flow and ended up going with the thrush welded, it just sounded better on my truck, but the ultra flow flowed better thats for sure
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