1G Exhaust Leak

[1glaserturbo]

This goes along with my thread in the ecu managment.

I found out last night that the lower right hand stud on my exhaust manifold was missing a nut, causing it to leak a bit. Would this cause my o2 sensor to have false readings?

What I'm asking is, I had my car tuned all the way down to only 2 counts of knock one day, took it to the track another, and pulled so much timing that it wasn't even funny. I did a boost leak test and the car easily held 18lbs with minimal leaking from the throttle body seals, or atleast that's where it seemed.

I also recently replaced the knock sensor, but we will have to see.




Chris

 

[mirkoelek]

This goes along with my thread in the ecu managment.

I found out last night that the lower right hand stud on my exhaust manifold was missing a nut, causing it to leak a bit. Would this cause my o2 sensor to have false readings?

What I'm asking is, I had my car tuned all the way down to only 2 counts of knock one day, took it to the track another, and pulled so much timing that it wasn't even funny. I did a boost leak test and the car easily held 18lbs with minimal leaking from the throttle body seals, or atleast that's where it seemed.

I also recently replaced the knock sensor, but we will have to see.




Chris

Yes it will affect it, regarding how bigg is the hole. If you were missing only one nut and all other were there you probally didnt have that big leak. Exhaust leak you can hear easy, i wonder if there was any why you couldnt hear it and notice it. Other thing, at WOT O2 readings are not important. If your timing was pulling is somethign different, you've got some knock ( intercooler size, high boost, low octane gas, lack of tunnig etc..)

 

[missouri_dsm]

Yes it will affect it, regarding how bigg is the hole. If you were missing only one nut and all other were there you probally didnt have that big leak. Exhaust leak you can hear easy, i wonder if there was any why you couldnt hear it and notice it. Other thing, at WOT O2 readings are not important. If your timing was pulling is somethign different, you've got some knock ( intercooler size, high boost, low octane gas, lack of tunnig etc..)

Wot O2 readings are important, Just like timing and knock. Replace the nut on the exaust manifold, any exhaust leak before the turbo can affect performance and tuning by a lot even the small ones.

 

[mirkoelek]

Wot O2 readings are important, Just like timing and knock. Replace the nut on the exaust manifold, any exhaust leak before the turbo can affect performance and tuning by a lot even the small ones.

When you are at WOT, its open loop. Your ECU doesnt need, read and uses O2 reading.

 

[1glaserturbo]

I replaced the nut, and now the leak is gone. I explained pretty much most of it in my post in Ecu Managment about what happened. Thanks though!