01 Astro P0101B, P0404B, ABS light

I'm back with my nemesis, an 01 Chevy Astro with 150k miles 4.3 auto . Appx 3k ago I had both heads replaced due to cracks and causing missfires. Now it is surging at highway speeds, with no current codes, but history codes P0101B, P0404B and the driver says that the ABS light comes on and goes off intermittantly. All the tests for the mass air flow in the GM manual test good and seem to be pointing toward the VCM. Any thoughts or ideas?

404 is an egr valve code! Likely the cause of your misfires all along. The abs code will have to be scanned but it's likely a bad speed sensor and or bearing. An internal vaccum leak caused by a stuck egr valve could generate a MAF code unless your tests are wrong and it's still no good.

I pulled the history codes for ABS and are as follows, C0265, C0245, C0241, C0251, C0246, C0252, all codes say EBCM control valve circuit. There are no current ABS codes. I'm going to swap a mass air flow, and an EGR valve and drive, see if I can duplicate. I have a good running van in for a trans change. Thanks Jeff for your help any ideas why so many different codes for the same thing?

maybe a wiring issue to the abs module. What are you using to access the abs codes?

I am using an SPX OTC Nemisys. It seems to give just enough info to keep me guessing.

yeah some aftermarket scan tools, even professional level are sketchy at best for abs work. My own snap on scanner is the same way.

Took back to dealer since they replaced both heads back in Dec. The new cat that I replaced at the same time had failed. They warantied the cat and I replaced yesterday all codes are gone at this time. Fingers crossed as this machine sure seems to have some ghosts, as it is the newest and one of the lowest mileage vans I have. Thanks Jeff.