Sup Mod keeping the peace
Join Date: Dec 2004
Location: NJ (Philadelphia area)
An easy test for converter plugging is done with a vacuum gauge. Connect the gauge to a source of intake vacuum on the intake manifold. Note the reading at idle, then raise and hold engine speed at 3,000. The needle will drop when you first open the throttle, but should then rise and stabilize. If the vacuum reading starts to drop, pressure may be backing up in the exhaust system.
Also while you have the vacuum gauge connected, with the engine fully warmed up, the reading at idle should be 18 - 20 InHg. At 3,000 RPM, it should be around 21 InHg. If readings are under 18 InHg, check the intake manifold nuts to make sure they are tight. Also check the intake plenum bellows at the throttle valve and at the MAF for cracks or loose clamps.
KA-T for life, yo!