does anyone know how you can tell if your loosing backpressure ?

 

A loss in torque would be the biggest sign, but what makes you think you're losing backpressure? Is your exhaust missing some vital components, such as the headers?

 

i have a AEM cold air, obx headers, 2'5in catback, with quad magnaflow, aasco light flywheel

 

You shouldnt have a problem with backpressure.

 

it only dynoed 200whp

 

Backpressure would only effect torque down low. But those numbers are not right at all. What dyno?

 

Your low dyno numbers are most likely the result of something maintenance related; stuff like a clogged cat, bad O2 sensors and so on. Loss of backpressure is a stretch without you feeling a loss of low end torque