Alright, well i just got two flowmaster mufflers installed, and it turns out i have 6 cats...is that normal?

i have other friends with GTs and they only had 2-4 cats...

would having 6 cats affect my car a lot?

i am noticing that my MPG is low, i mean low

i just filled my tank last night, and i drove about 30 miles...and im at half a tank now

all i have installed is two flowmaster mufflers and a short ram intake

can anyone help?

 

6 cats are normal. The 96-98 had 6 while 99+ had 4. Now for intake, are you refering to a cold air intake or a intake manifold?

 

im thinking he means short ram air intake--

30 miles to a half tank thats crazy but 30 miles to a half tank is about3-5 mpg....how do u drive the car as in do you drive around wot alot an stuff or what?

on my 96 with me driving it at what i consider my normal driving (gettin on it here an ther and driving respectably when needed) i can easily get 20-22 mpg and most of my driving is city driving...

does your car throw any codes.

 

ok im goin 2 have to say either ur gauge is broken or u have a hole in ur gas tank dumping all that expensive gas all over the street cause hummerrs get more than 30 miles to the half tank

 

In that case, check you MAF, it might be clogged w/ dirt, oil, etc. Also, is the check engine light on? Also, when you put the exhaust on, did you double check the clearances? While you are at it, check to see if your gauge is accurate. When you have a 1/4 tank left, fill her up, you should see that about 10 gallons were pumped.

 

also could be a bad fuel sender & float asbly or a bad fuel gauge in the dash. look for fuel leaks, one common place is the fuel tank filler pipe grommet at the tank.

 

+1 my 95 v6 had that, but would only leak if at an angle (like going up my driveway) so when I got to the top it owuld smell like a little bit of gasoline.
One time I was picking up my g/f from the train and parked my car on the side of the road at an incline, and fuel leaked everywhere lol... we fixed it soon afterwards thank god.

 

i drive normal

i drive on mostly main roads, which are 45mph

i usually drive between 46-49mph, on cruise control because i was told it would save gas

i barely get on it, just for the fact it would waste the gas i have

i have checked my MAF, and its clean

but ill look into the other solutions you all have given me and ill see what i can do, but my car throws no codes

 

is your car an auto or manual?

 

Cruise control does not save gas, especially if you have a manual. Just use the pedal since you can better compensate for hills. Also, how many miles are on your car?

 

it is an automatic

and it has 87500 miles

the car runs perfect, except for the gas issues

 

Are you're filters clean (air and fuel)? Also, check the spark plugs.

 

also at 87k the O2's are @ at the end of ther life span and should be replaced, a bad O2 will cause poor miliage and will not always throw a code. and since its an auto, what condition is the trans in? any slipping issues?

 

o2 sensors? i think that may be my problem

how many do i have in my exhaust? i heard from other people i have 4, but others tell me i have 2

also how much do they cost?

on the trans question, the trans feels smooth with every shift, but sometimes it shifts a little hard and slips occasionally

 

You have 4. 2 Before the cats and 2 after.

 

4 huh

ok, do you know how much they run by?

also, can and exhaust shop put them in or what

 

not correct, you only have 2 O2 sensors and they are before the cats. after the cats there are 2 O2 "Monitors" and they just measure the cats efficency. the ones ahead of the cats (O2 sensors) are the ones you need to worrie about and replace, we have them in stock if you need

 

But if the rear ones go bad, wouldn't that cause the MIL to come on and therefore kill mileage?

 

it would trip a code and set off the MIL but should not effect fuel mileage like the O2 sensors would. we sell 10 X's more O2's than monitors, so I would start there.

+ I see where he had mufflers installed, were they welded in? sometimes welding on a car wthout disconecting the batt + & - cables can cause issues wth sensitive electronic sensors.

 

I see, that's another thing learned...

 

ok thanks guys

randy, how much would they cost?

 

I'll do them at $69.00 each + shipping