horrible mpg and weird idle drop

Gerbil21

Original poster
Member
May 28, 2014
839
uploadfromtaptalk1428878099355.JPG
 

gmcman

Member
Dec 12, 2011
4,656
I had the Walker Quiet flow and I lost 2-3MPG over stock. There's another Walker that another rmember used and had good results. The Quiet flow has a much smaller diameter in the muffler, not sure about the resonator but my best MPG's was with the OE system.
 

Gerbil21

Original poster
Member
May 28, 2014
839
gmcman said:
I had the Walker Quiet flow and I lost 2-3MPG over stock. There's another Walker that another rmember used and had good results. The Quiet flow has a much smaller diameter in the muffler, not sure about the resonator but my best MPG's was with the OE system.
Yea I was surprised to see how much of a reduction there was in pipe I.d inside the resonator
 

gmcman

Member
Dec 12, 2011
4,656
Gerbil21 said:
Yea I was surprised to see how much of a reduction there was in pipe I.d inside the resonator
You should see the muffler, it chokes the 2.5 or 2.75" ID we have down to about 1 1/2"

Needless to say I got rid of it rather quickly.
 

Gerbil21

Original poster
Member
May 28, 2014
839
gmcman said:
You should see the muffler, it chokes the 2.5 or 2.75" ID we have down to about 1 1/2"

Needless to say I got rid of it rather quickly.
Wow that's horrible and seeing how the resonator was connected to the exhaust I'm guessing it was a whole bolt on and the muffler may of been too I got to check

Is the branding on top or bottom? the resonators's was on top making it impossible to see.
 

Gerbil21

Original poster
Member
May 28, 2014
839

Gerbil21

Original poster
Member
May 28, 2014
839
Ok I got around to check the muffler and it's original it's welded at the back. Could the original muffler be bad inside? I'm going to put the endoscope camera through the tail pipe tomorrow and take a look
 

Gerbil21

Original poster
Member
May 28, 2014
839
Well it's been a while since I've posted here but so far from what I've done I have not gotten any noticeable mpg increase until a week ago.

Last week I took the throttle body from the 02 engine my brother got in his engine swap and replaced mines with it after a good cleaning. One thing I have noticed just by looking at the two was that on the original one the throttle plate goes past the top a bit. (I'll put a pic later) that gap would of had been enough to let extra air in which would of made the o2 sensor think it's lean which would add more fuel.

Since I've changed it, mpg's have increased from barley struggling low 9mpg to high 10's to low 11's also it drives a bit better too.

I've originally changed the throttle body for a 1-2 shift issue on the chance the TPS was bad but it wasn't, the shifts do feel a bit better thought.

Now I need to replace the map sensor too with the 02 sensor, My throttle body and intake was covered in oil when i first got the car so it could affect it and if it didn't and it still works good then it dosent matter either way.

Also I need to swap the 02 exhaust manifold since mines has a cemented in O2 with bad threads and the rear bolts are broken so the gasket would be leaking meaning bad O2 readings. I just need to get a new gasket, bolts, O2 sensor, and manifold studs

I have also been thinking of replacing the drive shift from a 02 since they all had aluminum drive shafts vs our steel driveshafts, I also need to get stock high springs for the rear.
 

Sparky

Member
Dec 4, 2011
12,927
Gerbil21 said:
Ok it's been a while since I've posted here but
.................?
 

Gerbil21

Original poster
Member
May 28, 2014
839

Gerbil21

Original poster
Member
May 28, 2014
839
ok so just an update, took a trip upstate this weekend and averaged 18.6mpg. my brothers 05 tb got 20mpg,we both went around 75mph but i did have some catching up to do in traffic and got to 4k rpm about 3 times and also went 85mph about 5 times and 90mph about twice so considering that i got great mpg from a 4600lb suv with z71 springs giving a good bit of rake(bad for aerodynamics) and me and my mom 260lb and 150lb,

he has sagging rear springs so he is leveled and his weight was the same as us, the only difference between the trucks is his engine has 94k(replacement engine) iirc and has 16" rims vs my 17" rims both are 4wd with 3.42
 

gmcman

Member
Dec 12, 2011
4,656
If you're getting 18.6 MPG between 75 and 85 MPH, then I would think everything is working fine at hwy speeds for sure. The published 20 MPG surely isn't at 75 MPH. :smile:
 

Gerbil21

Original poster
Member
May 28, 2014
839
gmcman said:
If you're getting 18.6 MPG between 75 and 85 MPH, then I would think everything is working fine at hwy speeds for sure. The published 20 MPG surely isn't at 75 MPH. [emoji2]
Yea the mpg's great at highway speeds but at city it's amazing how fast it can drop. I need to move upstate lol

But I still have to change the exhaust manifold, gasket, bolts, and O2 that should help too
 

Gerbil21

Original poster
Member
May 28, 2014
839
Well it's been forever since I've updated this but not much has changed

I've only done a oil change

I have also been having a problem with the car being sluggish when warm but I've seemed to have fixed it by removing the intake snorkel which was a crap design either way

I have also been adding tc-w3 to the gas tank as a well known fuel additive, I've only just started the second tank so I should start seeing results by the end of this tank.
http://www.ls1.com/forums/f48/been-testing-oil-91206/
 

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