i am just wondering if you can lose power if you have an exhaust leak at the heads or anywhere.

 

yes...you can lose alot of power

 

thanks for the info. I have recently rebuilt my engine and put the sdpc vortec heads and base plate along with heddman shorty headers and a few other mods. the engine is just not performing like it should and i am hearing an exhaust leak but not sure where it is. it is a hissing sound. i believe it is coming from the flanges on the y-pipe or in back of the cat at the flange there. I didnt think an exhaust leak could make a big difference in the power. again thanks.

 

had a similar problem, does your hedmans have the gasketed flange or the ball flange. mine had the ball flange, could not make them stop leaking, particularly the one next to the O2 sensor. it would drive the computer nuts. fixed it with a pair of slp's !!!

 

i have gasket flanges but they are really hard to tighten and get a good seal. the flange behing the cat is a ball and i believe it may be leaking also. how did you find out it was messing your comp up. did you have it tested or something.

 

does it really affect performance if the leak is past the catalytic converter?

 

It all depends on where the leak is located in relation to the O2 sensor. If the O2 is downstream from the leak yes, it will cause problems. The O2 sensor will sense excess oxygen or a lean condition telling the injectors to increase in pulse width. This over a long term causes the engine to dump excess fuel into the cylinders without properly processing it. The result is more unburned HC's going down the tailpipe into the catalyst. This will eventually clog the catalyst and it will fail , not to mention choke the life out of your motor. Think of trying to exhale through a coffee stirrer .

Also, i am not sure about the newer third gens but i think they all had OBD1. OBDI does not include a catalyst efficiency monitor so if there is a leak after the cat and no catalyst monitor is there then no, there will be no performance lost or damages ensued. -Bob

 

Nice summary Bob.

 

Thank you.

 

EGG83 -- you have Hookers and flowmaster cat-back, did you change cats, and what did you use.......

 

Yes i have hooker shorties with a custom y-pipe, i have a catco hi-flow cat and a flowmaster 2.5'' cat-back exhaust. Yes i had to change cats because when i did my swap the old 2.8 cyl cat had been clogged up.