3 inch exhaust no cat=smoke?

[blueman803]

First time I have ever run a vehicle without a cat, should the exhaust gas be colorless? It has a slight grey hue to it, and I am not sure if this is a potential problem, running a little rich or what? Does the cat affect the color/consistency of the exhaust gas, and since there is no longer a cat the exhaust now has a greyish color?

 

[Dasamary]

Exaust gas will look a little blueish if you are burning some oil... Ive seen alot of cars who blow blue smoke and have a cat so im gonna guess the cat doesn't stop that. If the only thing you did was put on the new exhaust then i wouldn't worry to much.

 

[dalatinromeo]

First time I have ever run a vehicle without a cat, should the exhaust gas be colorless? It has a slight grey hue to it, and I am not sure if this is a potential problem, running a little rich or what? Does the cat affect the color/consistency of the exhaust gas, and since there is no longer a cat the exhaust now has a greyish color?

Yup if you have blue smoke you are burning oil.

 

[AWD_Launch]

First time I have ever run a vehicle without a cat, should the exhaust gas be colorless? It has a slight grey hue to it, and I am not sure if this is a potential problem, running a little rich or what? Does the cat affect the color/consistency of the exhaust gas, and since there is no longer a cat the exhaust now has a greyish color?

My exhaust did the same thing for a few days, give it about a week of regular driving and it should stop. At least mine did after the install.

 

[blueman803]

Alright, I am trying to narrow down where the smoke could be coming from. Disconnected the IC pipe from the throttle body and looked down the pipe, no oil. So its not my turbo seals. Rebuilt head and block, don't think its smoking from there. Valve seals would do it on startup, and it runs a little before it really starts. Rings shouldn't show up at idle right? They should also smoke worse when revved. So what does that leave? PCV valve pulling oil into the intake? Thats the only thing I can think of. It is definitely an overall grey color with a blueish hue. When I rev it up and let off the throttle it smokes black, I know thats rich and I am trying to tune that out. Maybe I lifted my headgasket and its a small amount of coolant? That would pull the oil off the walls too right?