3" exhaust system
every time I do a mod I get worse gas milage too. when I did my exhaust and intake it went way down only because I was pouring the **** to her just to hear the sound. so I bet thats what you are doing.
________
Zx14 vs hayabusa

________
Zx14 vs hayabusa
Last edited by jonnymagnum; May 8, 2011 at 03:17 AM.
unfortunatly i dont beat on the truck. lol, i baby the thing cuz i do drive so much and my gf is always w me and she hates driving fast. so yeah, the truck is babied. im taking the muffler off and getting a stock tho i think. i also looked at the wires and to my surprise its the originals! 90,000 miles on original wires cap rotor and plugs. so im guessing that that is a contributing factor to the decreased gas mileage. when installing the muffler i noticed that the cat was loose from the pipe in front. so that wud have been less pressure to flow thru the cat. i tightened that up. but idk wat to do, im going to start w the tune up kit thats for sure.
ORIGINAL: sprtsfrk
unfortunatly i dont beat on the truck. lol, i baby the thing cuz i do drive so much and my gf is always w me and she hates driving fast. so yeah, the truck is babied. im taking the muffler off and getting a stock tho i think. i also looked at the wires and to my surprise its the originals! 90,000 miles on original wires cap rotor and plugs. so im guessing that that is a contributing factor to the decreased gas mileage. when installing the muffler i noticed that the cat was loose from the pipe in front. so that wud have been less pressure to flow thru the cat. i tightened that up. but idk wat to do, im going to start w the tune up kit thats for sure.
unfortunatly i dont beat on the truck. lol, i baby the thing cuz i do drive so much and my gf is always w me and she hates driving fast. so yeah, the truck is babied. im taking the muffler off and getting a stock tho i think. i also looked at the wires and to my surprise its the originals! 90,000 miles on original wires cap rotor and plugs. so im guessing that that is a contributing factor to the decreased gas mileage. when installing the muffler i noticed that the cat was loose from the pipe in front. so that wud have been less pressure to flow thru the cat. i tightened that up. but idk wat to do, im going to start w the tune up kit thats for sure.
i have the same 3" dynomax catback on my 3.9 and it sounds great. and no the 3" is not too big because the 3" pipe doesnt come into play until after the headers, y pipe. and cat... you wont lose any low end, in fact i believe i gained some, but thats just a judgement. my 1/4 mile times did improve slightly, so at least i know i didnt hurt any performance, and i now get around 20 mpg with mixed city/highway driving. dont get a flowmaster 40, its a waste of money.


