bad exhaust smell?

[91-gsx]

hey you guys, i was just wondering if you dont have a cat, does your exhaust smell really bad and does it give you a headache due to the smell? the only reason i ask this is because i had a cutout welded in right at the first bend in my exhaust, and the electric cutout leaks some of the exhaust while i am driving and it smells bad and gives me a headache. i understand that the exhaust flow is excellent because i have no exhaust, but i am starting to think i made a mistake and have ruined the downpipe. any help or ideas due to why the exhaust smells so bad or if you guys know of something to do with the cut out, and get the elbow back in my downpipe.
thanks

 

[silver eclipse]

The smell may be due to running to rich. but you need to worrie about the head ache, its most likely from carbon monoxide, do you tend to start getting tired/sleepy as well. Its very dangerous, check for any leaks into the car, cuz a cut out shouldnt really becausing that, but if it is check into correcting it, weld the cut out shut.
-chad

 

[larsrya8]

I was always a fan of getting the exhaust out the back of the car, but that's just me. Seeing that you have a '91 I'm not surprised the exhaust is able to get through the floor of the car. Until you can fix the problem I would drive with your windows open or not use the cut out.

 

[91-gsx]

do you guys think it might be because of the o2 sensor? i have not heard of anybody else going through this? i have heard that if the exhaust smell is bad or it makes you dizzy and get headaches like mine does, it usually is the cat. the car also idles badly and whenever i gun the car and come to slow down the car like dies, and it dies sometimes when i try to drive the car. i think it is my o2 sensor??? maybe if anybody has gone through this please help, or if you have any ideas it would be great. the only reason i got the cutout is when i have a bigger turbo, the turbo would spool a lot faster and the car would have better top end with the cut out open, but i have come to notice that the cutout has taken a lot of torque from my car and it feels faster with the cutout closed??? this does not make sense though, right?
anyway thanks for the help, i hope i do not have to get rid of the downpipe or anything.

 

[larsrya8]

i have heard that if the exhaust smell is bad or it makes you dizzy and get headaches like mine does, it usually is the cat.

Using a cut out before the catalytic converter has the same effect as a catalytic converter that isn't working. Sometimes a cat will smell a bit after the car has sat for a long time (months) but it clears up after a few days. Raw exhaust has plenty of carbon monoxide in it to give you a headache and is dangerous.

the car also idles badly and whenever i gun the car and come to slow down the car like dies, and it dies sometimes when i try to drive the car.

This is could be caused by the car running rich. Are you using a S-AFC or equivalent to tune with? Your profile only lists a chipped ECU. Chipped ECUs give you a starting point to tune from, but you need a S-AFC to fine tune things. What do your O2 volts look like while cruising? Logging your O2 volts is a good way to determine whether the sensor is working or not.

the only reason i got the cutout is when i have a bigger turbo, the turbo would spool a lot faster and the car would have better top end with the cut out open, but i have come to notice that the cutout has taken a lot of torque from my car and it feels faster with the cutout closed???

Maybe it's all psychological. With the cut out open the car gets way louder, and therefore you expect it to go faster, but the 14b isn't a big turbo so you aren't.

anyway thanks for the help, i hope i do not have to get rid of the downpipe or anything.

Unless you can find a way to stop the exhaust from getting inside the car you might have to.

 

[91-gsx]

in general you guys i am having a lot of small problems with my car, sometimes i just feel like giving up on this thing but i love fast cars and this is a car that i can actually make fast. if i give up on this car, that means i give up on making cars faster in general. here is the list, i understand it is out of place in this thread, but bear with me because it relates to it. the car has a problem with the idle and cold starts, that is due to the fact that i took the fuel pressure solenoid off because it was not allowing the fuel pressure to go up with more boost, so i was seeing knock and when i took it off my knock count dropped considerably. then there is the fact that my trims change all of the time, almost everytime i start the car. my 750cc injectors are working at 84% duty cycle on a 14b at 21psi on pump. i cannot turn down the boost because if i turn the boost down with the exhaust cut out it Will not matter, the least boost i can run with the exhaust cut out open is 21, but when i close it i can run less boost but the downpipe becomes a really big restriction due to the fact that it is at the first bend on the downpipe, so it is like the exhaust has to hit a wall before it goes out. the next thing this brings me to is the fact that the exhaust cutout is smelly and gives me a headache when it is closed, and when it is open you get really light headed and feel like crap. i cannot run a exhaust around here because they hate rice rockets around here. last of all the car spends a lot of gas even though i have the trims a little above 100%, signifying lean condition. and the rpms drop so fast when i come to a stop, that the car dies, or the rpms drop past 500 rpms and the car feels like it is going to die. this is basically it you guys, it is a long list and i understand if you do not want to read it, but for those guys that have read this, i really need your help, please do not close this plea for help thread down.
thanks

 

[Turbocharged]

Some suggestions:

1. Get an exhaust
2. Turn the boost down (see no. 1)
3. 84% injector duty on a 14b at 21 psi = RICH. I dont see that injector duty that high at my 680's at 21 psi on the 50 trim.
4. Set you global fuel trims (see DSMlink for details)
5. You FPS has nothing to do with the problems you are having
6. If the car uses a lot of gas it is not running lean.

Basic maintenance:

1. plugs
2. wire
3. compression test
4. intake leak test

Having exhaust leak into your car is just plain dangereous. CO is colorless and tasteless but deadly... headaches should be a sign...

 

[91-gsx]

about the 14b at 21psi, your right, my injectors should definitely not be used up as much as they are. i just dont know what it is.... it seems that i have my fuel trims together, but then my gas mileage sucks and the injectors are at 84% DC.... it doesn't make sense. i have new plugs and wires and everything. i do not modify before doing basic things like timing belt change and all, I'm new to tuning but not new to cars. the exhaust will be brought back to its previous state, I'm going to take out the cutout. it is really high flow but it too high flow for the 14b because the car feels slower with it open and the boost cannot stay under 21, which is not a good number to run on a 14b.... i am sure i have leaks in my intake manifold, but i do not know were to even start with that. should i take the throttle body off and put new seals on? the piping held my pressure test until the 1g bov opened on its own, so that should be fine. but the intake manifold would not hold any boost over 4psi. thanks for the help turbocharged, that is why i started posting here in the first place.
later

 

[91-gsx]

well i just got into an accident today on the way to the muffler shop to get my cutout off and put a 3" exhaust on. i was about to miss the exit on the highway and lost control of the car when i tried to go into it, the car oversteers a lot, damage to the front bumper and the radiator support, the hood latch, my intercooler piping and couplers, i hope to fix it tomorrow. i still want to keep the car though, it feels like i have one or two things out of place and the car will run really strong if i can get them in order, that is were you guys come into play. i dont see how i am going to make use of using the dsmlink website if i do not have dsmlink? i have a fpr, a maft, and logger to tune with. cannot afford more stuff for now, like you guys say tuning is everything, and i just have too much money into this car already to put in more without seeing the results i want. the car, although running rich, is very fast already, but i obviously do not have it anywhere near tuned, so please guide me you guys. i have a dsmchips stage 3 chip with injector compensation for my 750cc injectors, but i do not know what size to set the maft to? that would be a great first step for me.
i will be on here until i get things done the right way, i hope that you guys can bear with me and help.
thanks, and later

 

[Maglin]

You should check lower injector seals. Chances are they are shot and feel like plastic. So in vacuum you are sucking in unmetered air and running lean and your trims probably go over 100% tring to compensate for it. Then under boost you are pushing out metered air and running rich cause of it. I had the same problem and knew the problem just been to lazy to fix it. Your wastegate isn't large enough to handle an open downpipe and thus you get boost creep to 21 PSI. I had that very same issue as well. I went to a much bigger turbo and thought the 38mm wastegate internal would due but I was wrong. Still was creeping but to 28 PSI so I just tuned it for that boost level. You can't boost leak test your intake manifold because you will have intake valves open on at least one cylinder and thus it won't hold pressure as it will just exit elsewhere. And actually a really lean car gets horrible gas milage and produces some horendous smelling exhaust that is more toxic due to NOx emissions skyrocketing.

 

[91-gsx]

way ahead of you on the lower seals. they were leaking boost and i sealed them really well with silicone overnight. stopped leaking from there now. then why do people say do a leak test if it will never hold boost due to the valves being open? the tubing is leak free, i can check that easy, plus the bov is the only thing that opens when i keep pumping air in. i dont know at what pressure it opens but it is a 1g bov and should hold for the most part. ya the exhaust really smells bad, and i am going to get a 3" exhaust and sell my cutout and downpipe. it is really straight through, but the boost will always go up to 21psi and that is feasible or really tunable on a 14b with pump gas. i was going to get a methanol injection kit so that i can run those high boost levels on this turbo, but the smell is what is not going to go. and it is really bad, i use to love driving my car, but with this leak it is a guaranteed headache everytime i set foot in it. it also makes you smell like crap and your clothes too. as far as tuning, i hope i can make progress with the exhaust on and tuning at a lower boost. man do i hate that smell.
later you guys

 

[91-gsx]

hey you guys just and update. i got a 3" exhaust from the front to the back, through a magnaflow muffler, no resonators or anything. the back, or catback is press bent but the highest degree of bending was like 15 degrees. so it is really straight. but i am still having the problem with the really bad exhaust smell, it is not in the car with me any more but i do smell it sometimes when i am at a stop. the car gets way worse gas mileage sense the bad smell came around. another interesting thing that might point to the o2 sensor, is that the logger reads a o2 voltage of .76, but the car is bucking and running a really high injector duty cycle for a 14b. so my guess is the o2 sensor.
if anybody has another idea, please help.
thanks