cracked exhaust manifold

[jumaaneface]

So I'm 100% positive my exhaust manifold is cracked at my egr hookup and 2nd runner. Will this cause a lean code p0171?

 

[thecrash91]

yes, because that is where the o2 sensor reads your afrs, it would probably be best to just have it welded as aftermarket manifolds usually run $500+ im at 108k miles, and my car is decently modded and i have run 14+ lbs of boost for the majority of this cars life, so i dont think the stock manifold sucks, i think its just select units that get cracks. mine has zero cracks

 

[jumaaneface]

I figured it would cause it to run rich and keep me from building boost, which doesn't really happen. Just goes lean at idle. Something around 17.1afr
It was a great manifold. Only cracked shortly after my stock motor mounts gave up the ghost.

 

[thecrash91]

hmmm, it may not be cracked manifold then. i had a lean idle problem for a very long time and i thought id never figure it out, because majority of the time i never got check engine light. do you run aftermarket injectors by any chance? do you have any mods or are you stock? if so list them, as that will help greatly. my problem with lean idle was because of my injectors, i sent them out to get cleaned and that helped for a bit, but eventually the problem came back, turns out the injectors were shot, so i put in a new set and the problem never came back.

 

[jumaaneface]

They are stock injectors. I know for fact my manifold is cracked right above the o2 sensor as well as a bad exhaust Mani gasket. I've considered my injectors but I've had symptoms of an exhaust leak for a while. Just seems to have gotten worse out of nowhere.

Mods: vibrant turbo back fmic ssafc ATP wga and sri

My vac holds at 21 until my fan kicks on forcing hot air into my intake filter.

 

[thecrash91]

edit: nvm the manifold was sold.

 

[jumaaneface]

If you were talking about the pep Mani I bought that.

Just thought of something. Recently I put a breather filter on my crankvent. Would that suck in any unmetered air? Not to say my exhaust leak isn't an issue.

 

[Dr0]

the crank vent is for crankcase "pressure" and it shouldnt have any effect

 

[jumaaneface]

the crank vent is for crankcase "pressure" and it shouldnt have any effect

With a filter there instead of the hose attached to the intake it tripped a p0171 code and leaned out at idle when my cooling fans kicked on. Swapping back to the hose fixed it. Still dips rich when shifting and randomly occasionally because of my exhaust leak.

Problem fixed.

 

[2.0t03speed]

did you get me pm about testing the manifold?

 

[jumaaneface]

did you get me pm about testing the manifold?

Didn't get a pm from you bro