Bad MPG after top end rebuild and y pipe mod!!
 

alright ,ive cleaned my injectors very good,ive changed ;plugs,wires ,dist cap,rotor,ThrotlePositioningSensor(and yes this thing cost me alot) and i did a y pipe mod known as (chief pipe mod) alot of dudes did it before me,and im runing no cat,and my fuel filter is new and my air filter is cleaned (k&n).

the only thing i did not changed is the O2 sensor,witch i think is as old as the truck itself,could it only be only that little sensor thats doing all this??

i meen its really bad its even worst than before i did the rebuild,and i had a damn hole in exaust valve numb 6 and i had one driping injector and everything was dirty ,i meen wut the hell.i think i get around 10 or 11 miles per gallon in town.makes me nuts :con:

any sugestions?

I would certainly change the o2 sensor. A bad o2 sensor can have a major effect on your mileage (5-8 mpg). Definitely go with an OEM sensor.

:eeek: wow that much.. thats insane, i can get one for 112 can dollars,so it should be worth trying right.

try www.sparkplugs.com

Hmmmm new free flowing exhaust = less bottom end torque more top end hp due to lack of back pressure. Perhaps your problem is in your foot to get the truck going as fast as before but with 10 less torque.

I don't know, but this might say something about the problem. :)


Not trying to start a flame war, just a thought.

Katie
:)

These are 4 stroke engines, They dont need back pressure, They need velocity and scaveging affects.
2 stroke engines do.

I would say O2 sensor, Check the wires too, possibly may have pinched or burnt.
The O2 sensor is after the Y pipe right ?

yep the the O2 sensor is after the y pipe,as for my spark plugs ,. i got one of the best for my kind of vehicule ,heres the picture:
NGK IRIDIUM TIP,superiror to platinum. around 25 bux for two;

http://img227.imageshack.us/img227/6858/p1010019mw9.jpg
http://img211.imageshack.us/img211/1980/p1010020mk9.jpg

i havent changed my O2 sensor yet ,but i noticed something when checking my timming with a timming light, my TPS is NEW but i havent adjust it yet ,i just bolt it and leaved it like that,im trying to do it right now ,i hope its the cause .if not ill try to change 02 sensor.

*edit*
Im an idiot

Since he is from canada he would be hit with border charges..
would be cheaper just to pay more localy.

yea ive checked the prize and its 112 can bux for OEM sensor

Where from?

I was going to hit up lordco and get a NGK plug.

local savaria auto part, just like napa but less expensive.

sparkplugs.com has NGK for less than $100.

what is so horrible with bosch?
im running a bosh O2 on a 98 camry.

$200 sensor....

You dont need back pressure, is correct, what you need is hot enough exhaust for it to move fast. Hot air flows faster than cold air. Too much free flow at low RPM prevents your exhaust pipes from heating up sufficiently. This is one reason people that have headers wrap them.

Now, put a cat on your truck. :spank: Poisoning the air is not acceptable just because it makes you think you can go faster. Plenty of people drive with converters and don't have the problems you are having and they aren't contributing as much to lung disease. Driving without a cat is like driving a 2 stroke, and you should save that for riding your old motorcycles. :devil: