CEL codes

[JFP in PA]

Originally Posted by Jamesp

P0491 and P0492, secondary air system bank 1, secondary air system bank 2 :troll:

The electric air pump runs with a durametric

The car runs great

2003 S 6 speed

The engine was recently rebuilt from the crank out and the passages to the exhaust manifold were completely cleaned

Any idea how to troubleshoot the system or which part or condition might be the likely culprit?

P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
P0492 Secondary Air Injection System, Bank 2 - Insufficient Flow

Possible cause of fault
- Electrical fault in power supply or line between relay and secondary air injection pump
- Secondary air injection pump relay mechanically faulty
- Mechanical fault in electrical secondary air valve
- Pneumatic secondary air valve faulty/sluggish
- Electrical fault in secondary air injection pump
- Mechanical fault in secondary air injection pump or secondary air injection pump blocked
- Vacuum system leaking
- Air hose to secondary air injection pump slipped off or constricted

[Jamesp]

Originally Posted by JFP in PA

P0491 Secondary Air Injection System, Bank 1 - Insufficient Flow
P0492 Secondary Air Injection System, Bank 2 - Insufficient Flow

Possible cause of fault
- Electrical fault in power supply or line between relay and secondary air injection pump
- Secondary air injection pump relay mechanically faulty
- Mechanical fault in electrical secondary air valve
- Pneumatic secondary air valve faulty/sluggish
- Electrical fault in secondary air injection pump
- Mechanical fault in secondary air injection pump or secondary air injection pump blocked
- Vacuum system leaking
- Air hose to secondary air injection pump slipped off or constricted

Thanks, I'll start running down the items not associated with the secondary air injection pump as it runs with the durametric

[Jamesp]

So these CEL codes are killing me.

First, my car does not match the parts schematic which shows this:



My #3 from the diagram above has only one large hose from the SAI, I don't have a #7 or a #4.

I've replaced my version of #3 and #14 and am still throwing the code.

The check valve #2 works well and the system holds a vacuum for about 2 minutes when drawn down with a vacuum pump. It does slowly leak back to ambient but the leak is very small. Anyone have experience repairing this gem of a system? What could be causing the CEL?

[Luv2Box]

Have you checked the vacuum tank for leaks? Also check the little hoses that connect the tank to the system.

[Jamesp]

There is a very small vacuum leak, small to the tune of taking minutes for the system to leak back up from -20 mm hg.