YACT...Bad, Bad Problem

[dtmbb92]

This might not seem like a bad problem for you but it is for me. I have a 92 Ford Ranger. Back in January I had a new cadalitic converter, flowmaster exhaust and duel tail pipes put on my truck. Ever since then my truck exhaust has smelt like sh1t! Its kinda hard to cruise by girls with a truck that smells like sh1t! It smells like rotten eggs. if anyone knows of what might cause this please tell me.

 

[LordRaiden]

Do you have glaspacks on it or anything aside from the stuff you listed here? To smell like rotten eggs assumes that you're generating a form of methane or something that smells like methane. That usaully also means that something is burning itself off. But if it's been going that long, the pipes and other stuff might not be putting enough back preasure on the engine causing improper burn. Another thing might be that the CC is causing the issue. If it is, get it replaced. It should still be under warrenty. I'd contact whoever did your muffler job and have them take a look at it. What you're describing is not right.

 

[dtmbb92]

Originally posted by: LordRaiden
Do you have glaspacks on it or anything aside from the stuff you listed here? To smell like rotten eggs assumes that you're generating a form of methane or something that smells like methane. That usaully also means that something is burning itself off. But if it's been going that long, the pipes and other stuff might not be putting enough back preasure on the engine causing improper burn. Another thing might be that the CC is causing the issue. If it is, get it replaced. It should still be under warrenty. I'd contact whoever did your muffler job and have them take a look at it. What you're describing is not right.

all i have on it is what i listed

 

[Vic]

That kind of smell is sometimes typical of a bad catalytic converter. Why don't you take it back to the shop who did the work and have them check it out? Didn't they give you some type of warranty?

 

[Feldenak]

Originally posted by: LordRaiden
Do you have glaspacks on it or anything aside from the stuff you listed here? To smell like rotten eggs assumes that you're generating a form of methane or something that smells like methane. That usaully also means that something is burning itself off. But if it's been going that long, the pipes and other stuff might not be putting enough back preasure on the engine causing improper burn. Another thing might be that the CC is causing the issue. If it is, get it replaced. It should still be under warrenty. I'd contact whoever did your muffler job and have them take a look at it. What you're describing is not right.

I always thought the rotten eggs smell came from sulfur?

 

[dtmbb92]

Originally posted by: Vic
That kind of smell is sometimes typical of a bad catalytic converter. Why don't you take it back to the shop who did the work and have them check it out? Didn't they give you some type of warranty?

i'm not sure if i have a warranty..i'll see if i do and then post again later

 

[Cyberian]

Originally posted by: LordRaiden
Do you have glaspacks on it or anything aside from the stuff you listed here? To smell like rotten eggs assumes that you're generating a form of methane or something that smells like methane. That usaully also means that something is burning itself off. But if it's been going that long, the pipes and other stuff might not be putting enough back preasure on the engine causing improper burn. Another thing might be that the CC is causing the issue. If it is, get it replaced. It should still be under warrenty. I'd contact whoever did your muffler job and have them take a look at it. What you're describing is not right.

I don't understand how back pressure would affect combustion.
I thought that a good exhaust system was designed to reduce back pressure and therefore increase performance.

 

[speed01]

Normally, the "rotten egg" smell is from the cat being bad. I would take it back to the place you had the exhaust done and have it replaced. If you had the dual exhaust added after the cat you might not have enough back pressure for the cat to burn hot enough thus clogging it up. I would suggest having it replaced with a high flow design.

Speed

 

[Eli]

Originally posted by: Cyberian

Originally posted by: LordRaiden
Do you have glaspacks on it or anything aside from the stuff you listed here? To smell like rotten eggs assumes that you're generating a form of methane or something that smells like methane. That usaully also means that something is burning itself off. But if it's been going that long, the pipes and other stuff might not be putting enough back preasure on the engine causing improper burn. Another thing might be that the CC is causing the issue. If it is, get it replaced. It should still be under warrenty. I'd contact whoever did your muffler job and have them take a look at it. What you're describing is not right.

I don't understand how back pressure would affect combustion.
I thought that a good exhaust system was designed to reduce back pressure and therefore increase performance.

It affects combustion, but in a negative way. You are correct.

 

[dtmbb92]

but i had a brand new cc put on...

 

[tm37]

Sorry you lost me when you said you were trying to pick up chicks in a 92 Ranger.

 

[Tsaico]

Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

 

[JC]

The catalytic converter frees up sulfur in the fuel. Have you tried switching brands of gas? Sometime's it's as simple as that.


JC

 

[Eli]

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

This makes no sense. The more efficient an engine pumps, the more power it will make.

If there is any restriction in exhaust flow, you will be reducing the engines pumping efficiency.

 

[JC]

Originally posted by: Eli

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

This makes no sense. The more efficient an engine pumps, the more power it will make.

If there is any restriction in exhaust flow, you will be reducing the engines pumping efficiency.

Well.....

Too little backpressure can result in overscavenging, and good fuel goes out the exhaust. A little backpressure helps keep it in the cylinder.

Obviously, this is not a prob with a race engine.


JC

 

[Grouchyoldguy]

Sulpher smell = unburned fuel in the cat I believe

 

[NorthRiver]

It does make sense. Without back pressure, every time you let off of the gas your engine would be sucking air in thru the exhaust. That is why people do not run straight pipes. You will kill your valves by leaving the system open. Top drags are the only ones running a straight pipe, but they are hammering the gas, and once the race is over the car is off. When top fuel cars are warming up you can see the fuel igniting out of the pipes. Just think what that is doing to your valves!

 

[optoman]

I get the rotten egg smell with certain blends of gas. Mobil is the main culprit, but only when they switch blends in the winter.

 

[Cyberian]

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

I have heard this many times and I still do not understand it. "How Stuff Works" claims the exact opposite to be true.
If you could point me someplace to read up on this theory maybe I will learn something.

 

[Eli]

Originally posted by: JC

Originally posted by: Eli

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

This makes no sense. The more efficient an engine pumps, the more power it will make.

If there is any restriction in exhaust flow, you will be reducing the engines pumping efficiency.

Well.....

Too little backpressure can result in overscavenging, and good fuel goes out the exhaust. A little backpressure helps keep it in the cylinder.

Obviously, this is not a prob with a race engine.


JC

Yeah, I can understand that I guess.

It's all in the design of the engine. The exhaust system design, that is. Wouldn't you get the most power out of straight headers, that let the cylinders scavenge fully? You would have to have the valve overlap set so that you didn't suck any fuel out of the cylinder I guess..

 

[IamElectro]

As mentioned above try switching brands of gas

 

[Eli]

Originally posted by: Cyberian

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

I have heard this many times and I still do not understand it. "How Stuff Works" claims the exact opposite to be true.
If you could point me someplace to read up on this theory maybe I will learn something.

I concur, it doesen't make much sense... Backpressure is going to raise temperatures in the exhaust system, not letting the exhaust flow freely.. I don't see how free flowing gasses could burn up an exhaust valve, vs. gas that's slightly compressed and not flowing so freely.

 

[JC]

Originally posted by: Eli

Originally posted by: JC

Originally posted by: Eli

Originally posted by: Tsaico
Incorrect actually. You need a certain amount of back pressure, otherwise you will lose torque. Maintaining the right amount of back pressure is important for smaller gas combustion engines, especially at lower or idle speeds. If you are at a high speed, then it isn't so bad, might actually help you, but at low engine speeds, you will not only lose torque but you can actually burn up your exhasut valves in worst case scenarios.

This makes no sense. The more efficient an engine pumps, the more power it will make.

If there is any restriction in exhaust flow, you will be reducing the engines pumping efficiency.

Well.....

Too little backpressure can result in overscavenging, and good fuel goes out the exhaust. A little backpressure helps keep it in the cylinder.

Obviously, this is not a prob with a race engine.


JC

Yeah, I can understand that I guess.

It's all in the design of the engine. The exhaust system design, that is. Wouldn't you get the most power out of straight headers, that let the cylinders scavenge fully? You would have to have the valve overlap set so that you didn't suck any fuel out of the cylinder I guess..

It's a tradeoff. Lotsa overlap, open exhaust + high RPM makes good power, good scavenging. But the overlap kills the lowend torque, much of the fuel goes right out the exhaust valve during overlap. Less overlap= less wasted fuel, more lowend torque, but less high-end HP.

 

[dtmbb92]

Originally posted by: IamElectro
As mentioned above try switching brands of gas

you mean instead of putting regular unleaded in my truck i should put premium?

 

[dtmbb92]

Originally posted by: tm37
Sorry you lost me when you said you were trying to pick up chicks in a 92 Ranger.

i've done it before!