Wow I can post. Long time reader first time able to poster and wouldn't you know the day I can finally post I actually have a problem. I have an 01 with Imagine Auto stage one chip and DV valves. Today I was driving and got a CEL. I checked the codes and they are p492 and p491. I have heard that this has somehing to do wih the secondary air intake. My boost reading still reads .8 to 1 but the car does not feel like it has any boost anymore. Anyone know what these codes are? Anyone have a rough idea of what would be involved to fix this? Am I looking at a major problem? The CEL came on about a week and a half after I had the new DV's put in. Thanks in advance.

 

2665 P0492 0-78.2 page 1
p0492
Printed in Germany – 6, 2002
0-78.2 P0492
Secondary Air Injection System, Bank 2 – Below Limit
Diagnosis conditions
• Intake air temperature 4.5 - 60 °C
• Engine temperature 4.5 - 102 °C
• Mass air flow 36 - 150 kg/h
• Engine starting temperature less than 42 °C
• Altitude correction factor greater than 0.75
• Oxygen sensors 1 and 2 ahead of TWC are ready for operation
• The secondary air injection pump is switched on
• Diagnosis has not yet taken place during this cycle

Possible fault cause
♦ Secondary air injection pump is not triggered
♦ Secondary air injection pump does not work
♦ Air supply lines restricted
♦ Electric change-over valve does not function
♦ Air change-over valve does not function
♦ Vacuum system leaking

Affected terminals
III/11 and III/14

page 2
p0492
Diagnosis/Troubleshooting
Secondary air diagnosis can be activated with the Porsche System Tester 2 in the "Short test" menu.
Work instruction Display OK If not OK

1 Activate secondary air
pump
♦ Remove relay of secondary air
injection pump.
♦ Jumper terminals 30 and 87.
♦ The secondary air pump must
be running (audible function).
– or
♦ Connect and switch on Porsche
System Tester 2.
♦ Select DME.
♦ Call up "Drive links" menu.
♦ Select "Secondary air pump".
♦ Activate secondary air pump
(audible function).

Step 3.
Step 2.

2 Check triggering of secondary
air pump
♦ Check fuse (Maxi Fuse) of AIR
pump (on relay carrier 2).
♦ Remove relay of AIR pump (on
relay carrier 2).
♦ Measure voltage between pin 3
and ground
♦ Push relay back on.
Battery voltage. Check wire from pin
2 to DME control
module pin III/11 for
continuity.
♦ Remove connector of AIR pump.
♦ Measure voltage at pin 1 and pin
2
Battery voltage.

3 Check vacuum system for
leaks
Seal vacuum system

4 Check electric changeover
valve
♦ Remove two-pole connector of
electric change-over valve.
♦ Trigger AIR pump with Porsche
System Tester 2.
♦ Measure voltage at pin 1 and pin
2
Battery voltage.
♦ Remove vacuum hose of electric
change-over valve with the
engine running.
Vacuum must be
present
Note!
DME 7.8
DME 7.8
0

5 Check air change-over
valve
♦ Run engine briefly to produce
vacuum.
♦ Activate secondary air pump.
♦ Remove vacuum hose of air
change-over valve.
Vacuum must be
present
♦ After activation, check air
change-over valve for continuity

6 Check air supply lines for
blockage
Work instruction Display OK If not OK

 

Thanks for the printout!

 

I've same codes after EVO stage 2 + V-flow. Dealer already replace new MAF for me but those codes still come up. I read Todd suggest replace Bosch FR6LDC plug will fix it. Can anyone confrim this? My car will go to dealer to re-check this week!

 

SAI fault, most likely a vacuum hose is off @ DV or the solenoid, or an internal leak in the DV's (diaphram/ "o-ring side" )

 

jayster you are the million dollar winner! It was the hose from the diverter valve. The tech said that the valves sit higher and the hose was rubbing against something that popped it off. The put another piece of rubber in between the hose and the metal piece and so it would not rub anymore. Not sre if that is really going to hold it in place but they seem to think it will be ok. Only cost me 60 bucks so I am happy. If it comes off again they said they will fix it free of charge. The guy who test drove the car was amazed at the difference in power over stock with just replacing the dv's and doing the stage one chip flash. I can only imagine how much further I can go once I do the intake and exhaust. God I love this car!

 

Your welcome, and glad you like the car.
Let me know when you want to hotrod it