deverting the AIR pump for a Dyno Run

bcollid · 03-03-2010, 03:29 PM

Is there an easy way to force the AIR pump to NOT send air into the exhaust or Cat so that I can get an accurate Air/Fuel ready from a wideband O2 sensor when I go to the dyno next week

surfer92 · 03-04-2010, 02:36 PM

Air pump only runs when engine is cold, once warm pump shuts down.
If you want a cold run, disconnect the pump for dyno run.

brownc00 · 03-18-2010, 02:17 PM

Quote:

Originally Posted by bcollid

Is there an easy way to force the AIR pump to NOT send air into the exhaust or Cat so that I can get an accurate Air/Fuel ready from a wideband O2 sensor when I go to the dyno next week

I've read that the ECM will lean out the system a bit when it is running the AIR pump to keep the A/F ratio in line with the extra air coming in from the pump. According to the doc I read, they said you should change the program to not allow AIR pump to run untill 254 degrees. That should prevent it from ever coming on.