2g fwd Fuel trim malfunction??

[blackhawkgsx]

Hi i have searched for a definite reason as to why I keep getting a fuel trim malfunction code and didn't have much luck . after looking over my car for any thing that was wrong such as leaks cracks , ignition /fuel problems but only thing i came up with was a blown turbo and a hair line crack on my manifold !! so could the crack be causing this code?

the car also idles high when this code is on if i clear the code then the car idles fine.

if it helps any the car is a 95gst with 6bolt bottom end ,e3 16g e3 ,ex mani, smic,wally 255, 3" tbe no cat. I do notice when the cel is on my afr's drop to 16.9-17.5 at idle and some time between shifts go to --- other times between shifts it goes to 12-13 on my wideband ?

any one else have this issue?

 

[1995gsx20g]

iirc the code is p0170 correct?

this code can be caused by a bad o2 sensor or in your case a exhaust leak before the o2 sensor.

by chance are you running e85?

 

[blackhawkgsx]

No e85 ,93 octane and i just replaced both o2 sensors after a buddy of mine told me to get rid of the bosh sensors i had , so i took back the bosh and exchanged for the denso sensors. when i did that i did notice the afr's where richer .

So you say the crack in my exhaust manifold would cause this then? So time for a new manifold?

 

[Red4G63]

Is it a big crack or jus a hairline crack. If its a small crack check for other exhaust leaks. I had the same code. My exhaust leaked at the O2 housing where the downpipe bolts to.

 

[blackhawkgsx]

Its just a hair line crack and i only noticed when i took the manifold off to install ss oil feed. On the collector on the inside a piece if the manifold broke off went through my turbo & every thing now i have mega shaft play the crack is huge on the inside it looks like a spider web, but on the out side you barely see it ... so whats a good cheap manifold i can get , im low on funds after fixing most of the half ass work done to this car from the previous owner . Also thanks for the input guys!!!

 

[Red4G63]

forced performance was running a 175 deal on their manifold.. i dont know if they still are or not tho.