straight pipe = more gas?

[Cooper-97gst]

So i finally got my car running again, now im thinking of putting in a straight pipe. i had a friend mentioned it will kill my gas twice as fast...any truth to that? im sure the car will run sweet with it. im not worried about passing smog, got that part locked in. thoughts and opinions please!

 

[ajpm26]

The only thing it'll do is make your car very loud and annoying, but hey, your car not mine, if you like it, then go for it!

 

[Cooper-97gst]

really? it wouldnt up the power?

 

[2GFWDbeast]

bigger exhaust like 3 inch and tubular manifold or ported will up the power but just few most likely not even noticeable

 

[Absit]

Exhaust on an FI car can net some nice gains, ignoring the manifold, you can see up to 50 WHP on a well modded car from exhaust.

A straight pipe alone won't do much, but it shouldn't hurt fuel economy either unless your foot gets heavier..

 

[jwahl16]

Like any exhaust upgrade you will see more mpg (if you drive the same, not beating on it all the time) because there is less restriction. Therefore the motor doesn't have to work as hard = less fuel burned. That being said, i don't know if it will be that noticeable if your just removing the cat, but it definitely won't hurt mpgs

 

[Cooper-97gst]

well i already have a 3' exhaust and a tubelar exhaust manifold, (should update my profile) thats the reason i was thinking of doing it. a buddy of mine metioned that the 2nd o2 sensor after the cat will make me waste the extra gas

 

[Absit]

The 2nd O2 sensor in our cars doesn't affect fuel trims, it only checks the cat's function.

 

[2GFWDbeast]

well i already have a 3' exhaust and a tubelar exhaust manifold, (should update my profile) thats the reason i was thinking of doing it. a buddy of mine metioned that the 2nd o2 sensor after the cat will make me waste the extra gas

the second o2 sensor should be right on the downpipe

 

[Cooper-97gst]

i see guess im going with a straight pipe then.... thanks for the input.

 

[Absit]

No, it shouldn't. The first is in the O2 housing, the second is after the cat.

 

[GRAVEDIGGER]

Exhaust on an FI car can net some nice gains, ignoring the manifold, you can see up to 50 WHP on a well modded car from exhaust.
A straight pipe alone won't do much, but it shouldn't hurt fuel economy either unless your foot gets heavier..

Exactly. And your foot could get heavier as the exhaust tone can become intoxicating for some.

Like any exhaust upgrade you will see more mpg (if you drive the same, not beating on it all the time) because there is less restriction. Therefore the motor doesn't have to work as hard = less fuel burned. That being said, i don't know if it will be that noticeable if your just removing the cat, but it definitely won't hurt mpgs

Yes... definitely.

well i already have a 3' exhaust and a tubelar exhaust manifold, (should update my profile) thats the reason i was thinking of doing it. a buddy of mine metioned that the 2nd o2 sensor after the cat will make me waste the extra gas

Well then, what are you waiting for??

P.S. Quit listening to your buddy. He might mean well, but......

 

[2GFWDbeast]

No, it shouldn't. The first is in the O2 housing, the second is after the cat.

WHAT umm on my 1990 i have o2 on the downpipe i dont have a cat. And on my 97gst i had an o2 on the o2 housing right after turbo and o2 on the downpipe also with no cat on the car

 

[Absit]

WHAT umm on my 1990 i have o2 on the downpipe i dont have a cat. And on my 97gst i had an o2 on the o2 housing right after turbo and o2 on the downpipe also with no cat on the car

We're talking stock. If you didn't have a cat why did you have a second O2 sensor?

 

[2GFWDbeast]

We're talking stock. If you didn't have a cat why did you have a second O2 sensor?

o2 for ecu and o2 for wideband

 

[Absit]

o2 for ecu and o2 for wideband

... You don't think you should specify what you're talking about when we're discussing stock O2 sensor configurations and you want to add a completely useless comment that's contrary to the actual configuration?

 

[GRAVEDIGGER]

the second o2 sensor should be right on the downpipe

Nope

No, it shouldn't. The first is in the O2 housing, the second is after the cat.

Yeah

 

[xXEclipse]

Its gonna be really loud and can get annoying, Ive never heard of it effecting mileage, When i got my 3 inch, I got some boost creep, thats about the only difference "performance" wise

 

[bradselph]

Running cat delete here...

I would say no to the lose of MPGs.
But i lost a few because i find myself on it more just to hear the exhaust.