Absolutcobra

I'm confused....I bought this daily driver in hopes to save gas vs my Jeep.

It's a 97 Honda Civic LX Sedan with what I am told is a D17Y8 (best on fuel economy I am told as well)

the previous owner put on a ebay rice pipe cold air that is louder than all hell, and a ebay rice boy muffler. Are all cold air kits loud? because this one is obnoxniously loud and whistles.....is there a certain brand or model that is quiet or even stock sounding? would I be better off looking for a stock system and putting it back in?

I just did a tune up, new NGK platnium plugs, new wires, new cap & rotor, seafoamed the motor, and fuel injector cleaner, but right now I'm just past the half mark with all highway driving at 75mph and I'm only at 200 miles?? I realistically don't seeing me squeezing out another 120 or even 100miles...Is there something I am missing??

is it possible the rice cold air and muffler are hurting me?

also...the car will buck every so often at 3500rpm when I am just cruising on the highway? the tach just bounces down and the car kinda bucks and sputters, and when I give it more gas it clears up.


PLEASE HELP! I just want a good gas saver that's dependable!!!

Tzarinque

bad 02 sensors will give you shitty gas mileage but you didn't get a CEL which is weird. Cold air intakes shouldn't be too loud at all, there must be a hole in it somewhere.

Absolutcobra

there is no CEL, and from what it looks like, the CAI is probably not the one for this car because all the sensor bungs and such are electrical taped in

baller status

Does the check engine light come on when you first put the key in? Maybe the previous owner cut the light so he could sell it.

I think you should put the intake and exhaust back to stock, but it's not going to solve your fuel consumption problem.

BTW, your engine is a D16Y7. The absolute best fuel economy engine for that generation is the D16Y5 which came in the HX. The HX also has better pick up from a stop than the LX.

O2 sensors can be wearing out but not throw a CEL. But the best thing to do is to get the car properly diagnosed. You'll save money and frustration over just replacing parts at random people's suggestion over the internet.

Absolutcobra

thanks baller status.....

I'm actually about to take it to Advanced Auto parts to get it scanned and see what could be the problem.

at this point, I'm about ready to drive the Jeep again!

I guess we'll see though.

if it's 02 sensors....is it just better to buy the plug n play ones or get the universals and save like 20 bucks per?

blk92_d16

Yeah, I was about to say it's going to be a D16Y8...which isn't the best motor/tranny combo for fuel mileage. Fuel mileage won't be as good, especially at fwy speeds, because of the gear ratio of the trans. Crusing at 65 on the hwy, what rpm are you at in 5th?

blk92_d16

Oh, BTW...did the previous owner say anything about an engine swap? Cuz that car should have the D16Y7, which is more fuel efficient and has longer gears which are better @ fwy speeds. Check the front of the block for the casting code and let us know!

Absolutcobra

I apologize for thinking it was a "Y8"

but it is indeed a D16Y7....stamped right on the block.

I just took it to Advanced Auto parts and they hooked it up to their scanner and it showed nothing. I asked the guy if the o2 sensor could be jacked up and he said that it might be clogged but still working?

I'm out of ideas....would the timing chain hurt this? I was told that I might need to replace that....

Malakai

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Absolutcobra &raquo;</TD></TR><TR><TD CLASS="quote">I apologize for thinking it was a "Y8"

but it is indeed a D16Y7....stamped right on the block.

I just took it to Advanced Auto parts and they hooked it up to their scanner and it showed nothing. I asked the guy if the o2 sensor could be jacked up and he said that it might be clogged but still working?

I'm out of ideas....would the timing chain hurt this? I was told that I might need to replace that....

</TD></TR></TABLE>

U might want to rethink about who is telling you this info. There is no chain on this motor, nor will it help to replace it.

Malakai

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tzarinque &raquo;</TD></TR><TR><TD CLASS="quote">bad 02 sensors will give you shitty gas mileage but you didn't get a CEL which is weird. Cold air intakes shouldn't be too loud at all, there must be a hole in it somewhere. </TD></TR></TABLE>

yes CAI are loud. Probably the loudest style to put on. I doubt there is a hole. N yes the whistle will generally accompany any a/m intake.

Also, with your "bucking" problem I would think to look into your timing. Make sure that is set properly.

tha_badguy

u fvcked up buying anything from a ricer...

Absolutcobra

I'm going to try the IACV cleaning tonight when I get home, but I don't think that would really hurt gas mileage that much, would it?

I've searched the forums and looked into other peoples problems but so far I have come up empty.

Surely someone else has had this problem and figured it out or overlooked something they later found!

I'm really at a loss on why this car is getting such bad mileage

Relic1

a few things...
cleaning the IACV (unless you have idle issues) will do nothing. No need to do it. Plus you may damage it, so leave it alone unless it's causing problems.
Pull back the carpet on the pasenger side kick panel and read the digits after 37820- on the ECU. You may have something other than what should be in there causing this problems.

You're cat could be clogged, your right foot may be too big, you may drive up hill both ways in 2 feet of snow every day like my grandfather did to get to school... lol

Seriously though, the D16Y7 is not great on gas but it should be in the low 30s if you don't drive like a traffic light drag racer.

It is very possible that your O2 is going bad but isn't bad enough to set the CEL for it yet. It's also possible that the wiring is jacked around with enough to not set the CEL... common in cars that are bought with issues and wanted to turn them around fast for a quick buck, and not caring how they screw the next owner.

Absolutcobra

Relic1, thank you for the great post.

The funny thing is....I do not drive aggressively at all....I literally get on the highway and just either ease my way up to 75mph and then set the cruise or just keep my foot on it lightly to keep it at 75mph and the speed rarely changes as it's a pretty flat drive.

how would I know if my catalytic converter is clogged? if I get a replacement, should I just get a regular one or a high flow? the rice boy muffler is going to be replaced as well.

I am curious about the o2 sensor, but it's 80 each for both the upstream and downstream, and don't really want to throw $160 at it if that's not the problem, know what I mean? I really wish there was just an easy answer to my problem, but apparently there is not.

so far, I've done plugs, wires, cap&rotor, seafoamed, lucas fuel injector cleaner, and I just changed the pcv valve....

trying to get the cheap stuff out of the way first, but looks I've exhausted those to this point.

Absolutcobra

also, is there such a thing as a quiet CAI? and what brand?

the one on there is mickey moused together it seems...electrical tape everywhere.

I was looking at the K&N and Injen CAI's.....


I was next to another civic today with some kids in it, and his car was definately quieter than mine when he got on it....mine sounds like it's pissed off all the time, because it's roaring if the gas is depressed a little, and when the engine is under load the thing starts to hiss and whistle.

Relic1

does it run out of power when you run the RPMs up? (I mean obviously run out of power vs the normal just sort of gutless)
if it feels like the power stops above 5k then check the cat. If it still pulls as hard above 5k as it does below it then it's not the cat.

post cat O2 is for emissions only, does nothing for how the car runs.

unplug the primary O2 (pre-cat) make sure that you get two CELs. (1 & 41)

if all that checks out, replace the primary O2.

if that doesn't fix it, it has to be something off the wall. Brakes dragging, wheel bearing going out, axle getting ready to fail, etc.

BTW, a cold air intake will slightly increase the mpg, the general reason why it lowers most people mpg when they put one on is they like the sound it makes, so more wide open throttle runs, which dumps the mpg bad.
Noisy CAI may be solved by cleaning up the transitions and corners in the piping. The smoother the intake air path the quieter it will be. (think of how a whistle works)

Absolutcobra

the car actually drags a little until you get to about 2500 rpm and then feels like it's getting power.


now the tach says 7k redline but I shift about 3500rpm's and I wouldn't dare take the car to the redline .... the car is already screaming at 5k.....is that right? because it doesnt do much after 5k when I'm trying to pass and what not.


Modified by Absolutcobra at 4:27 PM 4/9/2008

Absolutcobra

btw, this is what is on the ECU


37820 - P2E - A02 - 9000 - 204371

Relic1

the D16Y7 makes 106hp@6200 and 103ft/lb@4600

You're obviously not the typical driver of hondas, don't be afraid of it. It will pull all the way up to 6500. If it doesn't there is something wrong other than the O2 sensor. (O2 sensor is not used when pushing hard on the throttle)

What do you mean by screaming above 5k?
My definition may be different than yours, I'm used to 9k red line and 5500 RPMs at 80mph in 5th. (low gearing)

Also if the intake is as rigged as you describe, the previous owner may have done something to the engine, exhaust or ECU.
Make sure there is a plug in the IAT sensor. It's located on the intake manifold somewhere, should be a two wire plug. If there's a sensor with no plug there is a good chance the previous owner installed a "chip" that tells the ECU that's it's cold outside and as a result it pushes in more fuel. It does nothing but lower the MPG.

the ECU is the right one, that's not the issue.

Absolutcobra

I own a Muskrat and my Jeep, which don't rev too high.....lol


I guess it's screaming because of that intake....one of my buddies who owns a SI says it almost sounds like I am hitting VTEC because of how loud it is. Let me try and paint a picture for you....I already have the ebay muffler on there....the intake at WOT can drown it out. I found the silencer for it in the trunk and put it in, so it's quiet...but with the intake still on, it's annoyingly loud. So that's why I was wondering if different companies made quieter ones....this is definately a ebay special CAI, because it's nothing more than a dull polished pipe, with yellow hosing, and a yellow ring around the throttle body, and the sensor you speak of is not even really in the intake, it's actually electrical taped to it....like the previous owner wrapped tape around the sensor and then proceeded to make his own kind of funnel that actually plugs into the hole on the pipe.

pumafeet10

oh and shifting at 3500 will def not betting you good mileage, that is certainly not easing your way to 75. Shift at about 2000rpm and if you want better mileage don't go over the limit the amount of power for a civic going 65 increaes exponentially when going 75 that will kill your mileage .

randerson0248

If this is the first tank of gas since you bought the car, I think you will be surprised by how litlle gas it will take to fill up from 1/2 tank.

At half tank on the gauge, I can not get more than 5.5 gallons in mine.

You may have nothing wrong regarding fuel mileage.

I'd be worried about the "bucking" at 3500 RPM. Change fuel filter.

Might have water condensation in the fuel tank.


Modified by randerson0248 at 6:43 PM 4/9/2008