# 91 Sentra 1.6 fuel economy high flow cat & muffler performance chip



## [email protected] (Dec 21, 2007)

Hello, i have a 91 Sentra 4 speed MANUAL. I am wanting to change out the muffler and the cat converter. i plan to change it from stock cat to either a fake cat or a high-flow cat. the high flow is cheaper, so i will probably get that and i want to use a high-flow muffler like a popular "can" muffler, with a silencer. I already changed out the stock air intake to a popular 3" round filter with a MAF adapter. I have a hole in the muffler, so i have to change that out, but i have NEVER installed a muffler before
*did anyone ever switch out the muffler or CAT, and do i need a welder?
*what is the best fuel economy out of a 91 sentra?
*does a performance chip from ebay help out with HP or Fuel economy?
*does anyone have the stock numbers from Nissan for the HP and fuel economy?

this is all i can find, which is NOT official the Nissan numbers:
Gas Mileage of 1991 Nissan Sentra


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## kizer24 (Mar 23, 2008)

First off welcome. If you are referring to one of the 20 dollar black boxes, then it is just a waste of money. As for the cat and muffler, you dont have to weld but it does a better job than the clamps and since the car is 14 years old the cat is prob pretty rusted and will be a PITA to get off. As for the gas mileage not sure what engine you have. The link you are looking at is for the sr20de. My car is the 1.6 and I had been able to get over 40 mpg.
Drove from Kansas City to Waco, TX with less than 2 tanks. Still had over a quarter tank left on the second tank.


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## [email protected] (Dec 21, 2007)

i have the 1.6 dual cam 4 speed MANUAL. It is geared really low, too low for normal driving, like the highway. I am not really sure how great my gas mileage is, BC i dont know the exact fuel capacity of the tank, and i dont want to risk running out of gas completely. I think i get about 320miles to a tank of gas.-this is when the needle is directly on "E". I know that the Honda Civic 1.5 is supposed to get something like 45 miles to the gallon. -and this is with the new fuel ratings posted by the government. and what i saw from the government was that the sentra gets like 30 or so, not so hot. 

****if u get 40 miles to a gallon, is yours a manual 4 or 5 speed, or an automatic? and is your Sentra stock, or just an air intake?
I plan to use a "sawzall" saw to take off the exhaust. and using the flexible exhaust at Advance Auto Parts for about $20 for 6 foot.


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## greenbean699 (Jan 18, 2004)

your tank holds 13.3 gallons


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## kizer24 (Mar 23, 2008)

I have intake, header, short shifter, cleaned IACV, MAF, and throttle body. Other than that just the usual tune-up style maintenance. 5 speed. Be carefull with just cutting off the exhaust. My MPG went down a little with the header.


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## [email protected] (Dec 21, 2007)

i dont plan to change out the header, but as for the high flow cat, and the high flow "can" -type muffler, any improvements in HP and MPG? I hear stories like 4 cylinders need the back pressure to create HP, so i am not sure about the high flow cat and the high flow muffler. Chevy has the 200HP 3.3V6 Malibu that gets around 34-36 miles to the gallon, I love Nissan, and like the Chevy numbers, but i wish i could get my Sentra to put out these numbers.



kizer24 said:


> I have intake, header, short shifter, cleaned IACV, MAF, and throttle body. Other than that just the usual tune-up style maintenance. 5 speed. Be carefull with just cutting off the exhaust. My MPG went down a little with the header.


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## IanH (Feb 11, 2003)

Your high gear, 4th is the same as 4th in the 5 speed.
however these were economical, my son had one !!
if you look on cars.com there is a review from 1991 and they got 36 mpg on the highway with the automatic.
my 97 could get 36 mpg if i kept the speed down to about 70 !!!
it was rated at 39mpg highway when new, yes I looked a the original sticker when i sold it last month.


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## IanH (Feb 11, 2003)

BTW i just looked up the Malibu and the EPA highway for the 4 cylinder is 33 mpg, it looks like the V6 is 26 mpg hi-way but this is not clear, it gives 26-33 highway range but 33 for the 4 cylinder is clear, so the 26 must be the V6.


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## [email protected] (Dec 21, 2007)

My sister owns the 2005 Malibu and her Malibu car computer says 34 on the highway, and i think some site i found says 34-36 for the 200HP V6, I can not find it now, will post it if i can find it again. for some reason i thought it was a 3.3L instead of the 3.5L-which is in most of the specs. I may have seen the 35MPG on the 4 cyl and got them confused on the internet specs.

cars.com says 32 on highway with 3.5 V6 -not the 34-36 i was looking for, but her V6 car computer does read 34 MPG
2005 Chevrolet Malibu Standard Equipment and Specs


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## kizer24 (Mar 23, 2008)

Yeah freeing up the exhaust will help with HP but like I said, I noticed a drop in MPG with the header. By that I mean I freed up one of the most constrictive parts on the exhaust on our cars and lost MPG. So look at different posts on here about exhausts and see what other people have found.


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## sunnysentra (Jul 24, 2002)

don';t go any more than 2" mandrel bent tubing and if you hate drone, dn't buy the COffee can muffler. You need an Oval shape like a magnaflow. Have a shop weld up the hangers because unless you can do this, you will never be able to install this. 

I have a solution for a little backpressure relief. Buy the pacesetter system for 91-94. they fit just fine, no issues with quality now. they are fairly quiet muffler. looks like a stock exhaust with a big 4" tip. mounts easy. 

Pacesetter Performance Products - Exhaust Parts for Trucks and Cars 

You cannot reprogram the stock 91-94 1.6 computer period!!! you need the JWT ECU, but you have to run 91+ octane in the car, so there goes your hopes of spending less on gas. this is for performance only. 

Tune up the car with NGK plugs, new wires, Nissan Cap and Rotor. OHH.. Replace that ignition coil. they loose spark with high mileage and go bad. 

The CAT. replace with a factory replacement unit. they have little backpressure unless clogged. with no CAT. you get alot of carbon buildup in the pipes that blocks the openings in the muffler and seals off the glass packing and holes in the muffler!!!! The CAT actually allows less carbon to buildup. I pulled my CAT off and used a test pipe once. the sound is really loud and I got alot of black soot out the pipe. ALOT!!! The Cat works well. you will not loose performance unless its shot. 

Random technology makes direct fit CAT's for 91-94 sentras
CATCO makes some also

Chris 92 classic


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## [email protected] (Dec 21, 2007)

thanks for your input. I am trying to not spend a lot on a car i paid $50 bucks for. If i change out the stock cat, i will buy a performance cat off ebay, cheaper than the fake cat-(test tube). but the inlet and outlet for the performance cat is 2.25" made by Flowmmonster for around $50 shipped. the mufflers i was looking at are the basic "can" type, but they come with a "silencer" -that is removable. By "drone" are u referring to the sound that it produces? -and it will only affect the sound if i use the 2"+"mandrel bent tubing"? and does the can muffler increase or decrease HP and fuel mileage? I changed out the spark plugs, and i will start looking for deals on the wires and coil, assuming it is just replacing a part and no tweaking involved.


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## kizer24 (Mar 23, 2008)

Most the questions you are asking have been discussed on the forum. Search around on here to really get an idea of what you are looking at. I believe what he means by drone is the sound in the car when you are driving. It can get really bad with certain exhausts and at certain RPM's. Had a stealth that would make you want to kill yourself at 2500 rpms. Could just sit at lights and watch people shoot themselves behind me because of that perfect noise.... Got people off there cell phones really well.


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## seven_b13 (Oct 9, 2006)

OK.. *There is a whole lot of wrong facts and bad issues going around in here*.. I had a b13 XE for 3 years before I stepped up to my current 5spd b13 Se-r. 

TO address the OP (Original Poster): 
You have a long way in understanding car and how they work. From your post, it's obvious you don't even have car terminology or terms down. SO you need to slow things down. You should be researching and learning how your car drives and what the components are in it. I made some ridiculous things to my old b13 XE that I had to learn thru trial and error. BUT it was never RICED out. 

1. The way your planning to modify your car will result in a bad outcome and deem your car as "rice". 
2. You don't change your Cat and muffler and nothing else. You change the exhaust system. It might be difficult to find a cat back system for a 1.6, SO if your not going to spend the money to get a car specific system go to a GOOD exhaust shop and have them mandrel bend custom piping and put a GOOD muffler on the end. If you need a silencer then it's not a good muffler. It should range from about 250-350 to do this depending on shop. Do not go any bigger than a 2" diameter piping. Anything bigger will make you lose HP.
3.You don't call it a "can" muffler. As said by another poster, the oval or more rectangular kind are much quieter.. magnaflow, borla, etc.. research. DO NOT- I REPEAT- DO NOT BUY A PACESETTER EXHAUST (OR THE HEADER). That is the cheapest exhaust system ever and will rust out on you faster than Meinkie piping. 
4. STAY AWAY FROM EBAY FOR ENGINE COMPONENTS. Air intakes are ok and misc. small exterior or interior things. 
5. The EBAY performance chip crap is a waste of money. It's been researched and proven to do absolutely nothing. 
6. Your model with the Ga16de is in the range of about 90-95whp. 
7. Your 1st modification should be a Tune-up. 
8. As far as gas mileage. you have a 1.6L engine. you can't go much lower than that in economy. A full tank will last for a while. Modifying will make you lose mpg but it's very dependant on alot of other things. Don't worry about it. 
9. Do not go out buying a new ECU like another poster suggested. That is not a 1st mod. It is useless to add a JWT ecu to a stock car. Yeah you'll add a few HP but not the way it's suppose to. 
10. Research, Research and Research before you modify or Buy anything. 
11. I'd suggest once you've done research that you start with what we call, I/H/E = Intake/Header/Exhaust. It lets the car breath in and flow out to give you added HP.

Hope that helps..


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