Exhaust Post your questions and suggestions about stock or aftermarket exhaust setups. Third Gen exhaust sound files and videos!

Exhaust smell

Old 02-08-2019, 06:19 PM
  #1  
Senior Member
Thread Starter
iTrader: (3)
 
budget builder's Avatar
 
Join Date: Sep 2011
Location: nc
Posts: 832
Car: 91RS
Engine: carb'd 357 vortec
Transmission: 700r4
Axle/Gears: 3.42 posi
Exhaust smell

U can see in my sig what I'm working with. I have no cats. The exhaust smell is well in a word , cough cough cough... do I need a cat?

The exhaust is hooker shorty, 3in collectors into 2.5 y pipe, to single pipe to v force muffler to dual stainless steel pipe tips

Oh, no emissions test

Last edited by budget builder; 02-08-2019 at 06:22 PM.
budget builder is offline  
Old 02-09-2019, 08:03 AM
  #2  
Junior Member
 
Join Date: May 2018
Location: Wisconsin
Posts: 67
Car: 1989 Pontiac Firebird
Engine: Carb 305
Transmission: WCT5
Axle/Gears: 3.23Posi
Re: Exhaust smell

That would definitely cause an exhaust smell. You don't smell the exhaust when you are in the car, do you?
Firebirdwade is offline  
Old 02-09-2019, 01:30 PM
  #3  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: South Ms
Posts: 2,877
Car: 89 Pontiac
Engine: 5.0 FI
Transmission: 700R4. Shift kit+S10 TC
Axle/Gears: 3.73s Posi
Re: Exhaust smell

Check the charcoal canister. I have no cat and thought that was my problem also and it wound up being that charcoal canister. I don't run cats on ANY of my rides and have always taken them off even on my newer dailys and I do not have trouble with any gassy smell.
dmccain is offline  
Old 02-10-2019, 07:23 PM
  #4  
Senior Member
Thread Starter
iTrader: (3)
 
budget builder's Avatar
 
Join Date: Sep 2011
Location: nc
Posts: 832
Car: 91RS
Engine: carb'd 357 vortec
Transmission: 700r4
Axle/Gears: 3.42 posi
Re: Exhaust smell

Thk u
budget builder is offline  
Old 02-11-2019, 08:31 AM
  #5  
Supreme Member
 
Join Date: Oct 2004
Location: Henrietta NY
Posts: 3,809
Car: 1984 Trans Am L69
Engine: 355 Carbed V8 Patriot Vortec Heads
Transmission: WC T5 w/ Steel Support Plate
Axle/Gears: 3.42 10 Bolt Posi
Re: Exhaust smell

A lack of cat will make fuel smells when you are stationary or behind a running car. Anyone who tells you otherwise has been breathing too much carbon monoxide.
midias is offline  
Old 02-11-2019, 09:31 AM
  #6  
Senior Member
iTrader: (1)
 
GASPEDDLER's Avatar
 
Join Date: Mar 2014
Location: South Texas
Posts: 608
Car: '89 Iroc Z28-15,100 Original Miles
Engine: 350 TPI
Transmission: 700R4
Axle/Gears: Limited Slip, 2.77 Ratio
Re: Exhaust smell

I'm not running cats either and do notice stronger than normal fumes but mostly in the garage on startup when the tune is rich. Once she warm up she leans out and fumes are no where as bad. Have you checked for header leaks? I had a leak where the collector meets the pipe on the passenger side. You couldn't drive the car without smelling like the inside of a gas can.
GASPEDDLER is offline  
Old 02-11-2019, 12:00 PM
  #7  
Senior Member
Thread Starter
iTrader: (3)
 
budget builder's Avatar
 
Join Date: Sep 2011
Location: nc
Posts: 832
Car: 91RS
Engine: carb'd 357 vortec
Transmission: 700r4
Axle/Gears: 3.42 posi
Re: Exhaust smell

Originally Posted by midias View Post
A lack of cat will make fuel smells when you are stationary or behind a running car. Anyone who tells you otherwise has been breathing too much carbon monoxide.
hahahahahaha lol.... I'll check it out by this weekend. I gotta get this car squared away before I start on the 6.0... thx fellas
budget builder is offline  
Old 02-11-2019, 12:41 PM
  #8  
Supreme Member
 
dmccain's Avatar
 
Join Date: Mar 2014
Location: South Ms
Posts: 2,877
Car: 89 Pontiac
Engine: 5.0 FI
Transmission: 700R4. Shift kit+S10 TC
Axle/Gears: 3.73s Posi
Re: Exhaust smell

Originally Posted by midias View Post
A lack of cat will make fuel smells when you are stationary or behind a running car. Anyone who tells you otherwise has been breathing too much carbon monoxide.
Wow I must be breathing too much carbon monoxide. I haven't had a problem with exhaust smell in probably a dozen cars and trucks ive had with no cats. A leaky donut gasket and a charcoal canister were the culprits both times I noticed a scent.
dmccain is offline  
Old 02-13-2019, 08:50 AM
  #9  
Supreme Member
iTrader: (1)
 
Join Date: Sep 2005
Posts: 21,170
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Exhaust smell

Cars didn't have cats for A LONG TIME, and it wasn't ever a problem for any (or at least most) individual cars until people decided to "improve" them on their own.

In fact, quite to the contrary... when cats first appeared on 49-state cars (I wasn't living in California at the time) in the early 70s, THOSE were the ones that had the funny-smelling exhaust. You could smell em long after they had disappeared down the street.

I'd suggest starting out with making sure there are no leeeeeks. It doesn't take much, in the right place, to put exh gas where it can get sucked into the car by normal pass cabin venting. I'd also suggest making sure there are no leeeeeks in the car body itself, mostly toward the rear, like around the spare tire well, cargo hold, "glove box", wheel wells, back glass seal, etc. All of those areas can allow exh even from a completely functional exh system to be drawn into the car.

If you have "breathers", GET RID OF that, and put a functional, closed, properly set-up PCV system back on it. Crankcase vapors have a pretty hideous smell on their own.

This all is of course separate from fuel vapor aroma, such as canister issues.

Then, if the problem is more that the exh itself just smells rank to begin with, work on the tune. It's probably rich. A typical out-of-the-box Holley tune is NOTORIOUS for this. See the Holley Tuning sticky on the carb board.
sofakingdom is offline  
Old 02-13-2019, 03:35 PM
  #10  
Supreme Member
 
Kingtal0n's Avatar
 
Join Date: Mar 2001
Location: Miami
Posts: 2,828
Car: 240sx
Engine: whatever works
Transmission: 4l80e this year
Axle/Gears: 3.512
Re: Exhaust smell

Yep ^
Needs PCV
Needs a SEALED crankcase (pressure tested)
Needs a SEALED exhaust system and intake air path (pressure tested)
Need to run the exhaust all the way back (like a regular car)
Needs a modern combustion engine (after 2001~ is preferable, the older the engine gets the less technology in the combustion chamber/piston design, the less efficient combustion, the more leftover emissions "in theory")
Needs a good tune (should idle 14.7 to 15:1 usually for ideal 'smell')
Kingtal0n is offline  
Old 02-17-2019, 08:10 AM
  #11  
Senior Member
Thread Starter
iTrader: (3)
 
budget builder's Avatar
 
Join Date: Sep 2011
Location: nc
Posts: 832
Car: 91RS
Engine: carb'd 357 vortec
Transmission: 700r4
Axle/Gears: 3.42 posi
Re: Exhaust smell

10-4
budget builder is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
formula forever
Exhaust
13
11-07-2007 12:42 PM
jaretz28
Carburetors
10
10-07-2002 08:02 PM
Hellraiser
Exhaust
1
04-16-2001 12:02 PM
jeff
Exhaust
8
04-04-2001 09:47 PM
84Z
Exhaust
1
02-05-2001 07:22 PM


Thread Tools
Search this Thread
Quick Reply: Exhaust smell


Advertising
Featured Sponsors
Vendor Directory

Contact Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: