ported mass air flow sensor

[ProjectMM]

Well today i took out the Granatelli mass out and put back the factory (AC Delco) sensor back in. it fixed my bad idle issues and carpy gas mileage. But as i took it out I swapped the larger cones, and put them on the factory MAF. Now it pulls a check engine light. (System running lean) but the MAF on the scanner seems to be reading through the RPM, with a good reading.

Ported = 2.5 – 3 GPS
Factory (stock) 4.2 - 5 GPS

My question is there a way to get the computer to see the 4.2 GPS in the ported MAF?

[sprucegagt]

You can't swap to larger adapters on the stock MAF without ruining it's accuracy. That's why the SES light is on. The larger adapters change the airflow over the MAF elements versus the stock adapters. Put the stock adapters back on and clear the code. Your problem should go away.