Not Pass Inspection/Dealer has no clue

It kind of sounds like the fuel pressure regulator is the real problem here.

Is not the ECM, and catalytic converter under a extended emission warrenty? Maybe the chevy dealer may have looked into replacing these items first.

The fuel pressure regulator as Couger suggested seems plausible.

ok4550, you have still failed to make it clear to me in six paragraphs why any shop should turn down billable hours working on this car.

I’m sorry, but this should be covered under the emissions warranty.

This is probably why they’re “failing” to find the issue. Whatever component is bad, is covered.

Federal Emissions Performance Warranty

The Federal Emissions Performance Warranty covers the vehicle if it fails an emissions test in the first 2 years or 24,000 miles. Under these conditions most vehicles are already covered under the factory new vehicle warranty, so the 2 year 24,000 mile warranty is somewhat irrelevant. However many emissions components that can cause a vehicle to fail smog test, are covered up to 8 years or 80,000 miles, whichever occurs first.

Federal Emission Design and Defect Warranty

The Federal Emission Design and Defect Warranty covers the vehicle for a manufacturing design defect for an emissions component for the first 2 years or 24,000 miles. Like the performance warranty, specific major emissions components that fail due to a defect, may be covered up to 8 years of 80,000 miles.