Hi guys, I recently swapped a '06 engine into my '03. Everything runs fine, I did the swap properly. But the '06 doesn't have the secondary air injection ports, so I've had a CEL for it since the first time I started up the engine. After driving for 10k miles, the CEL suddenly went away. I thought that the bulb had burnt out, but it still turns on when I put the ket into the ON position. I don't know if I should be happy or worried.

 

Check Engine lights can go out without being cleared if the ECU doesnt see the fault after so many trips. You will still have the code in the ECU but it just doesn't have the MIL light. Happens in my gfs car all the time for her cat. convertor.

 

The OP's issue is very strange. It would fail the secondary AIR monitor every single time because the air has no where to go. (non ported head) The ELD senses high AIR pump motor resistance, and deems it a flow blockage and sets code P0411.

A possible cause is you developed a leak just large enough to mimmick the flow characteristics of the AP1 engine that used to be in the car.

This would be easy to mechanically bypass. By drilling a relief hole post-control valve on the back of the engine, one could mimmick the flow of the AP1 cylinder head. Using a scanner, enlarge the hole each morning until the AIR monitor runs and passes on one test.

With some time, I could figure out the hole size. This way someone putting a DBW cylinder head in a 2000-2005 car would have no CEL for lack of AIR head porting and you would have no P0411 code.

 

Wouldn't putting a Air Pump Simulator module do the same thing? You can get rid of the pump, current sensor, SAIV (if you have it), the relays, and the solenoid valve. In my mind it would get rid of your issue, and you'd be saving a good 20-30lbs of weight.

 

Yes an Izzy Engineering electric air pump simulator would cure all your problems as well.