996 TT 2002 tip with DTC p0491 p0492

[demarconstruction]

Hi after replacing the left oil reservior holding case for the turbo ive noticed the CEL with 2 codes p0491 p0492 my scan tool shows it as secondary air injection system could it have been from when we made the repairs?? any suggestions thanks

Edited October 24, 2009 by demarconstruction

[Loren]

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

Check the connector (perhaps they left it unplugged) then fuse (40A on relay panel near DME).

[demarconstruction]

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

Check the connector (perhaps they left it unplugged) then fuse (40A on relay panel near DME).

Thanks Loren

[Blue Monster]

My car just had the same codes, p0491 and p0492. I had them cleared and they have not come back. The weather was extremely cold that day, but not sure if that had anything to do with it. I can post my full readouts if anyone cares. Just wondering if anyone else had the same experience. Thanks.

--BM

[laalves]

My car just had the same codes, p0491 and p0492. I had them cleared and they have not come back. The weather was extremely cold that day, but not sure if that had anything to do with it. I can post my full readouts if anyone cares. Just wondering if anyone else had the same experience. Thanks.

--BM

I have. They came back. Took it to the dealer, they replaced "some valves" and the codes came back. Will take the car there again in March...

[Blue Monster]

Thanks, if I get the codes again, I'll post here, reading up on it, seems like a non-essential part of the car, heats up the catalytic converters, but if not working correctly it may not pass state inspection

[Blue Monster]

Thanks, if I get the codes again, I'll post here, reading up on it, seems like a non-essential part of the car, heats up the catalytic converters, but if not working correctly it may not pass state inspection

March 12th, still no codes, hopefully I haven't just jinxed myself....

[Blue Monster]

Funny, the codes just came back for the first time in 5yrs (looking at my old posts, had them cleared, let's hope for another 5yrs

[Blue Monster]

Just happened again after getting the car detailed and I remember it happened last time after I got it washed, so intermittent, but seems to be related to when the car gets water on it.

[Blue Monster]

and just happened again

[Loren]

Check the wiring and connectors to the secondary air pump.

If all look good then wiggle them some and see if you can make it happen.

If not, you may just have a worn out secondary air pump.

[Blue Monster]

Thank you