Measuring Exhaust Backpressure - VZ Alloytec190 2005

Measuring Exhaust Backpressure

(procedure obtained from Tuner. university. com)
"If you wanted to find the back pressure being caused by the catalytic converter, you simply plumb in the fitting
before the cat, do a WOT run and find the peak pressure. Then you come back, switch to the bung behind the
cat, and do another run. You should then be able to see the difference between the two."

I ran this in my VZ 2005 - exhaust catalysts never replaced - Odometer 245.500km - Alloytec 190 (In Brazil named Omega CD).

Note: In my VZ, I did not observe evidence of problems related to obstruction of catalysts. I present these data as a reference for possible use in diagnostics and, if appropriate, obtain critical comments from experts. I thank you in advance.

The results follow:

Pre-cat-left hand side
3000 rpm = 10 mbar = 0,14 psi
WOT = 110 mbar = 1,6 psi

Pos-cat-left hand side
3000 rpm = 2 mbar = 0,03
WOT = 50 mbar = 0,7 psi

Pre-cat-right hand side
3000 rpm = 10 mbar = 0,14 psi
WOT = 110 mbar = 1,6 psi

Pos-cat-right hand side
3000 rpm = 2 mbar = 0,03 psi
WOT = 50 mbar = 0,7 psi

This is it.

I just hope not to have to replace the catalysts of this car. In Brazil simply "does not exist" for replacement. (Original part for Holden Commodore VZ 2005).

Thks.