exhaust smell suggestions

[3tcpower]

So, I have posted a few times and on my problem, but in different variations. My car has a horrible exhaust smell at idle and it failed emissions a few months ago by a LARGE margin on all accounts.

The car appears to idle ok, but every now and then it sounds like there may be a hiccup. The few times I have driven it I hit 5 psi easily and it appears to maintain it. The mbc is set low, so 5 psi is expected by me. Also, I have done TMO logging and all sensors appear to respond correctly at idle and when reving.

I have replaced my wires, plugs and o2 sensor. My question is what are some other things I can look at? I will be doing a blt this weekend and I just want to know other things to check or do.

Thanks to anyone helping me to get my car legal soon,

 

[3tcpower]

Thanks. Need to figure everything that could be causing my issue. Also, with all my researching, a blt has only solved issues about 50 percent of the time. Just sick of working on the car to finally get to drive it.

 

[the_mork]

Buy some seafoam and run it through your engine. It will be good for the car and the white smoke will highlight any and all exhaust leaks. If you don't know what seafoam is or how to use it then use the search button, there is an extensive thread about it on here.

 

[Demon33]

So, I have posted a few times and on my problem, but in different variations. My car has a horrible exhaust smell at idle and it failed emissions a few months ago by a LARGE margin on all accounts.

The car appears to idle ok, but every now and then it sounds like there may be a hiccup. The few times I have driven it I hit 5 psi easily and it appears to maintain it. The mbc is set low, so 5 psi is expected by me. Also, I have done TMO logging and all sensors appear to respond correctly at idle and when reving.

I have replaced my wires, plugs and o2 sensor. My question is what are some other things I can look at? I will be doing a blt this weekend and I just want to know other things to check or do.

Thanks to anyone helping me to get my car legal soon,

What does the odor smell like? Rotten eggs? If so, it could be a sign that your catalytic converter is faulty or starting to go bad. A quick Google search netted a few results pointing to the catalytic converter as a possible cause. Try removing the catalytic converter and smelling the exhaust. If it smells better, there you go. Although I didn't see any information on the muffler as a possible cause of the bad smell, I guess it could still be possible. Maybe something crawled up in there and died. It could happen.

 

[GsXdSmKingGsX]

The smell of rotten eggs usually is coolant

 

[3tcpower]

I will probably try the seafoam as well.

The cat should be good. After I had it replaced a couple months ago is when I noticed the smell. The old one had deteriorated into a rattling mess. I just wish I could remove it to check. The shop decided to cut of the old one and weld a new one

 

[3tcpower]

Also, I wouldn't say its rotten eggs. Its just a funky smell and unfortunately not transmittable over the web. I assume its caused by it running rich cause my o2 voltages were high for the most part with the exception of the occasional dip like it was trying to correct it.

 

[chico904]

Are you burning oil or coolant?

 

[Demon33]

Also, I wouldn't say its rotten eggs. Its just a funky smell and unfortunately not transmittable over the web. I assume its caused by it running rich cause my o2 voltages were high for the most part with the exception of the occasional dip like it was trying to correct it.

If you think the smell is due to a rich conditon, try to disable one or more injectors either through your logger or physically disconnecting the injector electrical connector. This should cause your engine to run lean and if your hypothesis is correct, the smell of the exhaust should change.

 

[Demon33]

I will probably try the seafoam as well.

The cat should be good. After I had it replaced a couple months ago is when I noticed the smell. The old one had deteriorated into a rattling mess. I just wish I could remove it to check. The shop decided to cut of the old one and weld a new one

So why would you not suspect the catalytic converter? If the smell started when the cat was replaced, shouldn't you consider it a possible cause? We all know there are manufacturing defects in every industry. New parts don't always work as designed. I don't think catalytic converter manufacturing is immune to defects. I would still check it out to be absolutely certain it isn't the cause.

If you can't remove the cat because it's welded in, drop the down pipe momentarily to smell the exhaust. But being so close the oxygen sensor it might screw with your O2 readings. Just a suggestion.

 

[3tcpower]

I will try the injector disable. I played with that before just to make sure all injectors were behaving the same, and they were. I just never thought to smell the exhaust when doing it.

In regards to the cat, I will see about trying the dp. Do you think a defective cat, not worn, would cause a bad smell and failed emissions? I just figured that if the honeycomb is there it is all good till it clogs.

And again, thanks everyone for the input

 

[3tcpower]

Are you burning oil or coolant?

Not that I am aware of. My coolant level has stayed the same and there is not appearance of burned oil on the bumper or in decreasing oil level.

 

[Demon33]

I will try the injector disable. I played with that before just to make sure all injectors were behaving the same, and they were. I just never thought to smell the exhaust when doing it.

In regards to the cat, I will see about trying the dp. Do you think a defective cat, not worn, would cause a bad smell and failed emissions? I just figured that if the honeycomb is there it is all good till it clogs.

And again, thanks everyone for the input

Taken from a Google search here-

"There are a number of factors that affect the performance of your catalytic converter. The converter works in conjunction with your oxygen sensors to come up with the cleanest possible exhaust. As long as everything is operating as it should - engine at proper operating temp, air/fuel mixture optimized, no contaminants added to the exhaust - the system works really well. Throw a faulty O2 sensor into the mix and you have problems. Since the O2 sensor can alter your air/fuel mixture, it can kill your catalytic converter. If the mix is too lean, the converter won't have the right elements to clean the exhaust. Too rich and the converter will heat up to the point of melting, and trying to push exhaust through a solid block is tough. If your car burns oil or leaks coolant into the engine, these contaminants can collect on the ceramics inside the converter and cause it to clog. "

Not sure about the smell, as I've never experienced this before, but sure, you could fail emissions for several reasons related to the cat as described above. In addition, the catalyst inside the catalytic converter doesn't begin working until it reaches the proper operating temperature of about 400-600 degrees F.

 

[the_mork]

You could also be smelling crankcase. Do you use a catchcan or similar device? Check to make sure that your valve cover breather isn't somehow clogged and that your pcv system is in working order.

 

[3tcpower]

You could also be smelling crankcase. Do you use a catchcan or similar device? Check to make sure that your valve cover breather isn't somehow clogged and that your pcv system is in working order.

Thats another thing unchecked. Thanks. No catch can. Just stock stuff.

I will have to see what I can figure out with the exhaust.

 

[3tcpower]

So, I took somethings apart.....mostly so I could get the air filter and intake tube off. My turbo has no shaft play which is nice. But I am about to feel dumb. Where is the pcv valve on these cars? There is a tub coming of the valve cover on the passenger side that runs to the intake. I didn't see much else.

Also, what does the second tube on the intake go to? The one located directly below the valve cover hose.

Thanks again

 

[the_mork]

http://www.dsmtuners.com/forums/newbie-forum/229338-stupid-pcv-question.html

Is a pretty comprehensive thread with ideas on making a more durable system and plenty of general pcv discussion.