Exhaust Smells Shitty

[theKnifeArtist]

yeah, it smells. i wanna say it smells like bad fuel, but i dont wanna totally throw it off, doesnt seem to smell like coolant either..i was hinted it might be something with the cat..could an old cat make a bad smell? i have no idea how old this cat is..

 

[JustAnotherVictim]

Yes, cats can stink.

 

[theKnifeArtist]

does this give me an excuse of gut that bitch? would that make it not smell? its that honeycomb shit inside that would be causing a smell, no?

 

[bigunitpitcher22]

I think he was talking about an animal.

But, I have no idea, haven't had the problem

 

[JustAnotherVictim]

It's still possible that your car will smell even after you gut it.

You're still having problems with the bov so you should should probably work one thing at a time. Running rich will cause you emissions to smell more than usual also.
Check for exhaust leaks and things like that.

No smartass comment that time, lol.

 

[theKnifeArtist]

well i have the smell during idle, so i dont think its because it's rich..how would a spot an exhaust leak? it doesnt sound like its got a leak, its quiet as shit

 

[jetjock]

Probably H2S. Usually caused by a rich mixture.

 

[Tanya]

clogged cats, to me, usually smell like burnt mud. if you've ever droven through a nasty puddle or go muddin, you know what that smells like, heh

 

[jdub]

If you're running rich at idle, this will make the motor dying problem you're having with the SSQV worse.

 

[theKnifeArtist]

im pretty damn sure im not running rich at idle. would a video clip help show you?
how about a smell clip muhaha, kidding.

 

[jetjock]

What makes you so sure you aren't running rich? Have you measured it?

 

[theKnifeArtist]

i dont have a way of measuring it, i thought i knew how it looks, smells, sounds(bring on the comments)...i mean, im pretty much stock, stock injectors, stock afm..

 

[jetjock]

Stock is good. Means it'll be easy to fix because Toyo's engineering hasn't been hacked. They're really isn't an accurate way to know mixture without measuring it. If the engine was capable of holding a tight mixture on it's own it wouldn't need an EFI system and a feedback lambda loop. It's imperative to hold the mixture tight because the cat's life depends on it. Any codes? The TCCS is designed not to let this happen without telling you. H2S smells like rotten eggs, is that the smell?

 

[theKnifeArtist]

hmm you might be right, that might be the description i was tryin for.
no i dont have any codes

 

[jetjock]

Well, if the mixture varies even a little from what's correct and stays there for a certain time the O2 sensor will report that to the TCCS as a fault and should set one of two codes. It'll only do that if the igniton key has been cycled twice with the problem present both times. Maybe it's not a mixture problem after all. No way to tell without either measuring the exhaust stream or checking the O2 sensor signal. Based on no codes I'm going to go out on a limb and say it's not a mixture problem. The cat could be contaminated by some additive you put in the fuel or oil ie; the "seafoam syndrome". H2S is almost always caused by a rich mixture though. It's tough to know without doing some more digging. Run the engine at 2500 rpm for 10 minutes with the brake booster hose off and the O2 sensor unplugged. That'll drive the system lean and burn off anything that might be in the exhaust system or on the O2 sensor. It's an old trick used by emissions techs. Can't hurt anything to try.

 

[theKnifeArtist]

you mean the cat is actually fixable? im gonna try that brakebooster hose trick. with the brake booster hose...you mean the larger one on the upper right front of it, right?

 

[jetjock]

"Fixable" is a relative term. A modern cat is composed of a ceramic substrate covered with a wash coat of precious metals. If the wash coat on an intact substrate hasn't been overly contaminated and is contaminated with something that can be vaporized it's possible this'll work. It's a last ditch effort commonly used before changing a converter that's already been diagnosed as contaminated. Since yours has not it's even more of a shot in the dark but it won't hurt anything to try. Yes, the large brake booster hose. Disconnect the O2 sensor too so the system doesn't try to compensate by adding fuel. Run the engine with the car parked and see if the smell goes away. Then reconnect everything and see if it returns. If it does you're screwed without proper test gear.

 

[jdub]

What you're doing is taking the ability of the ECU to adjust mixture away by disconnecting it from the ECU...it goes to a fixed value. Disconnecting the booster line to the intake manifold creates a large vacuum leak, inducing unmetered air into the intake causing it to go lean. Lean = higher combustion temp = burn off contamination from the CAT media

 

[jetjock]

Yeah. It's still a crap shoot though because too much air will result in going too lean and EGT will fall. The booster hose is usually about right for a leak but he may need to go bigger or smaller by using a combination of hoses. But try the booster alone first because I'm not motivated enough to go out in the garage and fire up my 5 gas to see what's needed to get peak EGT at that RPM. He could really heat the cat by going the other way (rich) but that's risky. Frankly, I don't have a lot of faith this is going to solve his problem.

 

[theKnifeArtist]

well, its worth a shot, im gonna try it tommorrow, thanks for the help:icon_razz ill report back when i do it