I have a 2001 mustang GT. I installed a set of Off-road H-pipes and I lost power and it doesn't sound right at all. I wrote a forum on here a little while back about this car having a power loss. Well I never could figure out what it was, so I just quit thinking about it. Well when I installed the H-Pipes it magnified the power loss problem. I have the predator and I did turn off the rear O2 sensors, so that isn't the problem. I replaced the other two O2 sensors, but that didn't help. Anyone have any advice? God bless!
Bobby
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For the body without the spirit is dead, so faith without works is dead also. James 2:26 "2001 GT Convertible w/offroads, flowmasters and 4:10 gear"
Off-road mid pipes have been known to cause a loss down low. I have experienced this with both of my Stangs, more so with the 2V though, however they both pulled better up top . A high-flow catted mid-pipe provides just the right amount of back pressure and still gives a good increase in the upper rpm's.
It seems like it lost power through the entire range. I have an automatic trans. When I purchased the car it already had 2 1/4" flowmasters on it, but they are older and have a few places that are rusted through where axhaust is coming through. The car sounds horrible coming through the exhaust, I am thinking maybe the flomasters are bad?? I think I am going to go ahead and get the 2 1/2" flowmaster cat back system and see what that does. The car has a 4:10 gear and it didn't want to spin the tires after I put the pipes on it. I don't know, but I know I am regreting getting a 4.6 car, that was a terrible mistake, I should have stayed with the 5.0 cars, I never had the problems out of them that I am having out of this thing, blahhhh!!!
God bless!
Bobby
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For the body without the spirit is dead, so faith without works is dead also. James 2:26 "2001 GT Convertible w/offroads, flowmasters and 4:10 gear"
Does it miss at all? or is it just sluggish? If its just sluggish it sounds like a vacuum problem. Although my GT did the same thing and it turned out to be bad plugs and wires.
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1997 Mustang GT- Sniper NO2, Bassani Off-road X pipe, Flowmaster Catback, C Springs, tons of other little things-
if u do have a leak in the rusty flowmasters it will hurt power some what.. its a pressure lose in the exhaust... its usauly not as bad the farther back in the exhaust it is..like if it were a collector leak that would kill power.... but its is prolly makeing it sound like crape...so id start there if it were me...
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1996 mustang vortech v-2 sq blower with aftercooler 10psi, proffesional products 75mm tb and plenum,bbk long tubes,custom x-pipe,flowmaster cat back,3.73, optima red top in trunk,steeda clutch quadrant and fire wall adjuster,poly motor and trans mounts,alum drive shaft,maxium motorsports suspension,tubular k-member/arms, qa-1 struts and shocks,steeda cc plates,custom subframe connectors,welded torque boxes,t/a rearend cover,walbro255, b&m shifter/triax handle,sct tuner.90mm lighting mam
hmm u shoulda got X pipe first off...make sure all ur flanges are tightend and no pipes are disconnected. when i put the O/r X on my car the 21/2 clamp on the muffler heading to the tailpipe was disconnected and i felt a power loss then when i put new clamps on it and everything was tight and secure she ran fine and fast
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2001 Mustang Convertible (Cruise Car)...
2000 Mustang Coupe (Race Car)...
Well It's Enough To Kill ANY Of Those Jap Cars
"Real Cars Don't Power The Front Wheels, They Lift Them"
they will cause a slight loss of torque down low, but should definately wake up on the top end. I'd say you have a leak somewhere, did you replace the gasket between H pipe and manifold?
i agree with what mark says... it sounds like a leak to me. and just a side note i have noticed a lot of people "notice a power loss" when doing large exhaust upgrades.. mid pipes, headers, catback... im just going to point out that the extra noise and "loud factor" plays a little bit on your psyche and makes you think the car should have way more pull because you are hearing a lot more noise.. this is a typical thing with most people.. and realistically you wouldn't be able to FEEL a difference of even 20 horsepower from an exhaust change like that. the only way to know is to either run it at a track or get it on a dyno. but yeah i would say you most likely have an exhaust leak or something.. check that. and get rid of the slowmasters, thats your first problem lol.. jk man
I checked out my flowmasters a little closer and the guts in the right side muffler are shot and moving around inside the muffler. So I ordered the flowmaster 2 1/2" cat back system. I would guess that the messed up mufflers are probably my power loss problem and definately the terrible sound problem. Thanks for all the help everyone. I will let you all know how it turns out. The new pipes and mufflers will be here tomorrow and I will install them then or thursday. Thanks again everyone and God bless!
Bobby
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For the body without the spirit is dead, so faith without works is dead also. James 2:26 "2001 GT Convertible w/offroads, flowmasters and 4:10 gear"
well hopefully at least it sounds better!! bet it didnt sound to health lol.... good luck....
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1996 mustang vortech v-2 sq blower with aftercooler 10psi, proffesional products 75mm tb and plenum,bbk long tubes,custom x-pipe,flowmaster cat back,3.73, optima red top in trunk,steeda clutch quadrant and fire wall adjuster,poly motor and trans mounts,alum drive shaft,maxium motorsports suspension,tubular k-member/arms, qa-1 struts and shocks,steeda cc plates,custom subframe connectors,welded torque boxes,t/a rearend cover,walbro255, b&m shifter/triax handle,sct tuner.90mm lighting mam
I agree with Mark and Cobra, I have a 2000 gt with a mac 2 1/2 O/R H-pipe and a Flowmaster 2 1/2 40 catback. The car is an auto and after I put them on it sounded sloppy and smelled terrible, untill they broke in then if rolling slow (10-20mph) and stomping on the gas it would make the tires squeel. After a few weeks it started sounding different and power felt sluggish, so I retightened everything. I noticed almost every bolt had gotten very slightly loose and the passenger one comming off the header was almost compeletely off. A friend suggested to retighten everything then put on another bolt and tighten that one down (double bolt it or whatever). So after you get your new catback put on maybe retight everything and throw on and extra bolt.
An o/r mid-pipe and flows is what I consider an acquired taste. The guys that have it say they love it, I had it and hated it. From inside the car, 2000-2700 rpms sounded horrible, after that it sounded ok. I had the same results with a MAC catback. Once I put the catted x on, it sounded great.
"I checked out my flowmasters a little closer and the guts in the right side muffler are shot and moving around inside the muffler. So I ordered the flowmaster 2 1/2" cat back system. I would guess that the messed up mufflers are probably my power loss problem and definately the terrible sound problem. Thanks for all the help everyone. I will let you all know how it turns out. The new pipes and mufflers will be here tomorrow and I will install them then or thursday. Thanks again everyone and God bless!
Bobby"
jessus fvcking christ get rid of the god damn flowmasters they blow. why would you have a part from a company that is warranteed for life, everybody is telling you they suck, then they fvck up and you turn around and order the same fvcking thing....
god i hate flowmasters they are cheap and the whole argument i have ever made in the past about people just getting them because they believe they are the best thing in the world... this guy is proof of that.
i hate to sound like a dick but that was stupid on your part to turn right around and order flows again.
damn cobra, not trying to sound like a dick? doing a pretty crappy job at it. i haven't read a lot of opinions on build quality. all the "people saying they're crap" i've read so far on here is because people don't like the sound. saying everyone else has the same sound. if you don't like the sound, then don't buy them. if he does, then why shouldn't he? just because you like one brand better, for god knows what reason, and have made a million arguments supporting that brand, what makes your opinion fact? i personally want a different sound and may change mine. but not due to quality, they're fine. i know a lot of people who've had flowmasters for the life of their cars with no problems. it's only about sound.
Off-road H-Pipes = LESS power?!?! 
