I have a 2001 I just bought,and cut off catalytic converter and muffler to get better fuel mileage.the onboard computer said it was 20.1 mpg..but after cutting off muffler and catalytic converter,i dropped down to 16.4 mpg...Is this right? Do I need to put everything back on? there was no oxygen sensor or anything like that on converter..or is the onboard computer lieing to me..any Ideal on what i need to do.thanks for info..

 

The overhead isnt really accurate. The best way to do it is to hand calculate the mileage over a full tank.

 

i bet you are getting worse mpg due to the fact that youre using the go pedal more because you can hear it I know i did

 

2001 was not a cat, that's a resonator and a muffler. And I second what benroberts said......

Besides, dropping the exhaust will not likely yield a substantial gain in mileage that you will notice by inaccurate hand calc'ing or with the overhead inaccurate thing. The main factor there is attached to your right hip, attached to your right knee.......etc.

 

Agreed! I thought with my res gone and a free flow muffler I was already loud.
Till I decided, might as well try it, Bam! Love the sound, little worse mileage

 

Well.Im 46 years old..and I really do drive my truck with ease. Take off slow,to save transmisson,and fuel milage.I dont Slame it to the floor..too much motor for something to give!!ha I like to take care of my truck..it has to work for me,to make me money.ha but thanks guys..will put back muffler and cat. thanks

 

before you put the exhaust back on. I would run a tank full to see the mileage hand calculated.

 

As stated, it's not a cat, it's a resonator. 94-98 had catalytic converters....98.5-02 have resonators.
Removal of the exhaust components shoud have no effect on fuel mileage.
And it's true....heard it many times... a guy removes his exhaust system and then can't figure out why his mileage went down. It's usually due to pushin on the go-pedal harder because of the new found "excitement".
If your MPG's dropped, more than likey it's not because of the exhaust delete.

 

should add a tad bit of milage, not much though. Prolly only like .5 to 1 mpg if your lucky. I would never put it back on, let your truck breath, it will thank you for it.

 

Yea dont put it back in dishtech. If you drive nice and easy then youll have no prob with any worse mileage. And it will sound better to the people you pass walkin thats for sure.

 

Same thing happened when my cat. fell off......my mileage decreased for a period of time till I started letting off of the skinny pedal...now am getting anywhere from the high teens to the low twenties depending on what I'm hauling/towing and how heavy my right foot is.