HELP.. exhaust smells bad

Sup pplz.

i have a 94 civic dx with a super bad smell coming out the exhaust. a friend of mine told me the smell is like unburned fuel which i believe would explain my bad gas milage too.

i hooked up an air/fuel ration to it (at the o2 sensor) and the guage stays stuck on rich.

they car only recently started doing this.. i have also noticed that sometimes the check engine light goes on.. but when i turn off the car and turn it back off its gone, so i cant get an ecu reading.

what would cause this.. and what can i do to fix it.
is it the o2 sensor?


---- specs------
94 civic dx
sohc non-vtec engine
ractive headers
tenzo catback exhaust

[Wren57]

Could very well be the o2 sensor... the headers could be messing it up... do you still have the cats on there? If you took off the cats thats gonna be your problem... also if you have a lot of miles on the car you may wanna upgrade ur plugs (real cheap) to make better spark to burn more of the gas... thats all I can think of for now, lemme know how it turns out...

[ebpda9]

hmm, you can still retrieve the codes if the CEL is off, once it's been on. just do the regular codes retrieval procedure. i know my car used to do that in the winter, before getting a valve adjustament. how does the exhaust smell like ? does it smell like worn socks or so ?

are you sure your friend is right? if the smell is more like a bad smell and not a fuel smell and you're running rich, could also be a fouled cat. but the fumes would smell like rotten eggs and shit, so I'm sure you would've written that, instead.

actually.. now that i think about it.. it kinda does smell alot like rotten eggs.. all i know is that the smell is unbelievable

Originally posted by h82lose
actually.. now that i think about it.. it kinda does smell alot like rotten eggs.. all i know is that the smell is unbelievable

sounds (smells ) like a bad catalytic converter then. . . .

[nonovurbizniz]

keep in mind the most common problem that leads to a bad cat. is running rich. if your fuel mileage isn't what it should be you ARE running rich (that or your leaking gas)

so if the smell goes away after you replace the cat. DONT FORGET WHY IT HAPPENED. get the fuel issues straightened out as well. otherwise your gunna be getting a frequent buyer discount on yer cats

hahahaha.. nice..
yea. im getting the o2 sensor replaced first.. since thats the cause (my air/fuel guage stopped working because of the sensor)

then ill replace the cat..

have you guys seen the prices for o2's.. 160 from dealer.. 80$ aftermarket.. anybody have any issues with aftermarket o2 sensors?

(its a 4 wire bosch universal)

[Racing Rice]

Originally posted by h82lose
hahahaha.. nice..
yea. im getting the o2 sensor replaced first.. since thats the cause (my air/fuel guage stopped working because of the sensor)

then ill replace the cat..

have you guys seen the prices for o2's.. 160 from dealer.. 80$ aftermarket.. anybody have any issues with aftermarket o2 sensors?

(its a 4 wire bosch universal)

Screw bosch! I put two of them on my car any they both threw up different errors. If you can get one for 160 from the dealer do it. They told me it would be $225 or so.

WOAH 225$! now thats expensive, but it has to be done.

[Racing Rice]

Originally posted by h82lose
WOAH 225$! now thats expensive, but it has to be done.

Hasnt been done yet..

[Addict]

Originally posted by h82lose
WOAH 225$! now thats expensive, but it has to be done.

Yeah. Call around ALOT before you get one. I believe DENSO also makes sensors for our cars.....

[Racing Rice]

Originally posted by Civic_Addict

Yeah. Call around ALOT before you get one. I believe DENSO also makes sensors for our cars.....

That was my stock one..

Ok.. car is running super rich.. my Air/Fuel guage is solid rich.

i swapped the cat with a new one and swapped the header o2 sensor. also swapped the distributor cap and rotor.

today im changing the fuel filter, spark plugs and wires.

i dont know what else it can be and need help.

when i removed the old sensor and cat.. it was jet black! and its only going to be a matter of time before it happens again so i gotta get to the source


any ideas

[Addict]

Does it have any smoke coming out?

You might check your valve cover for leaks. Otherwise it could be the valves.

no smoke comes out.. i had the valves adjusted by a Honda tech. engine runs smooooth now.. but super RICH!

[pdiggitydogg]

throw a turbo on there w/ no fmu to lean it out lol jfwy

[Addict]

Originally posted by h82lose
no smoke comes out.. i had the valves adjusted by a Honda tech. engine runs smooooth now.. but super RICH!

Other than your A/F Gauge, how can you tell its running rich?

black soot all over the old Cat i took out and caked on the old o2 sensor.

i changed the plugs and wires today and they were caked too. Funny part is after i changed all that stuff, i reset the ecu and now the a/f guage is marking lean. so i might have fixed my problem. ill know for sure tomorrow when i take it for inspection again.

[Addict]

Originally posted by h82lose
black soot all over the old Cat i took out and caked on the old o2 sensor.

i changed the plugs and wires today and they were caked too. Funny part is after i changed all that stuff, i reset the ecu and now the a/f guage is marking lean. so i might have fixed my problem. ill know for sure tomorrow when i take it for inspection again.

Is it saying lean at idle?

Yeah those things you mentioned will definately cause problems.

ya.. right now the a/f guage has only one light lit up at idle
if i hit the gas, it will light up another 3 more or so, even if i bail on it.. other than that it will never reach the middle.

im looking into just buying a fuel pressure regulator so i can adjust it myself

ok the title is sumthing like "exhaust fumes smell bad"

i'm not even going to take the time and read any of the posts...

1. stop sniffin the exhaust fumes
2. clean your exhaust or make fuel mixture more lean (mom had same prob.)
3. it's hard as a b!tch to get high off them fumes... believe me.. takes a while....
4. that title is funny as hell... LOLOLOLOLOL!!


i had to edit this post 4 times... JEZUZ CHR!ST i'm dumb

wouldent like soot and stuff be caked on there anyway since exhaust leaves a residue, but what your saying is it might be more than you think should be with a new cat etc.