exhaust smokes on deceleration

[crrider80]

Hi guys. When i had my stock exhaust my exhaust smelled like rotten eggs most of the time when i come to a red light. When i got a catback and deleted the cat my car smells like gas/oil when i come to a light and smokes significantly more. The brown wire on my o2 sensor had broken off the clip so the o2 sensor isnt working properly. The car doesnt smoke when i'm on the gas. My intercooler pipes have oil in them tho. I revved the car with the oil cap off but didnt notice any air blowing by. What would cause my car to smoke like this? thanks
-steve

btw, i have a shortblock with approx 5k on it from lagged

 

[IHI-RHC7]

It sounds to me like the piston ring seal on the turbine shaft of the turbo.
However, with a non-functional O2 sensor, the car will run quite rich, which will cause the gas smell.
There are a few reasons why you can't smell it on accel. First would be the fact that you're moving and the guy behind you gets stuck with the smell, second would be that the TCCS ignores O2 input under heavy load and reverts to "safe" base maps, so it would run better when boosting than when cruising.
My first move would be to repair the O2 wiring, and then go from there.
Let us know how it turns out!
-Jake

 

[mrnickleye]

Also, worn oil rings on the pistons will cause oil burning on the decel because it cause a strong vacuum, and the worn rings can't wipe away the oil on the cylinder walls efficiently enough.:naughty:

 

[lagged]

if you dont see any oil smoke when youre accelerating you can be pretty sure its not the rings. that shortblock had a fresh rebuid!

 

[crrider80]

so i checked it out a few days ago and my accordian hose is oily as crap, and theres some sitting in the inlet of the turbo. I think its coming from the pcv pipe from the valve covers. Does anyone know what could cause this? how does the pcv system on our cars work? thanks
-Steve

 

[LilRedSupra]

Positive Crankcase Ventilation: Vents gas/oil blowby into the intake via intake tube to be burned through the motor during normal operation!

so i checked it out a few days ago and my accordian hose is oily as crap, and theres some sitting in the inlet of the turbo. I think its coming from the pcv pipe from the valve covers. Does anyone know what could cause this? how does the pcv system on our cars work? thanks
-Steve

 

[GrimJack]

And when it starts spitting a lot of oil in there, the rings are usually shot. Fire up the engine and pull off the oil cap, check if there is a lot of air getting pushed out of there.

 

[supra90turbo]

Worn valve stem seals will also cause oil burning on decel, fwiw.
Doesn't answer well to your other problems though.

 

[Bishop92t]

Could also be blown turbo seals. Remove the accordian hose and check the turbo for shaft play.