roadsession

I have a recurring CEL P0491 and PO492.
Any ideas?
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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

redridge

this code is a PIA to troubleshoot.... turned out my cats were bad.

roadsession

Went back to my dealer. It was a cracked vacuum tubing -diagnosed and replaced free of charge in 30 mins.

Benefits of a good relationship with the dealer...

Arne Klinge

Hello roadsession

I have a friend with these errors and misfiring with the engine running rough. Have diagnosed with Durametric. Did you experience misfires and rough running?

PS: he does not run his car now and the fault codes emerges straight after clearing them and running the engine.

roadsession

Yes it was running rough with these codes and yes after replacing vacuum lines all was good

AA717driver

Just got off the phone with my Indy. Similar problem (started a thread about it last week). And, I had a similar problem before and he found a cracked vacuum tube.

Good luck and can't wait for a resuloution for your problem.

TC

JMLavoie

Can The 'vacuum tube' be identified in any way?

Ahsai

This may help https://rennlist.com/forums/996-foru...omponents.html
You can use a hand vacuum pump to track the vacuum leak and even verify the SAI valve's operation.

Arne Klinge

As I mentioned in above post, we had these error codes and misfire codes as well. Were not able to check the vacuum system as our knowledge of this stops at "eeeeeehh that looks OK to me, or like a spaghetti monster".

So we moved over to changing all spark plugs and coils, success all around.

Ahsai

The spark plugs and coils fixed the SAI related (P0491/P0492) codes as well? That is interesting as those parts should have nothing to do with these codes.

TeknikL

Is this the same thing? doesn't seem to be since it says malfunction

P0491
Raw code: 0491
ECU: Engine control unit
Status: Confirmed
OBDII: Secondary air injection (AIR) system, bank 1 - malfunction

============2==============
P0492
Raw code: 0492
ECU: Engine control unit
Status: Confirmed
OBDII: Secondary air injection (AIR) system, bank 2 - malfunction

DBJoe996

I just love a 12 year old thread resurrection...just like it was yesterday

Eurocarguy911

We can add cracked head to this list. It's what happened to mine.