96 850 n/a | vacuum line connection at airbox | P0410

[jdw]

Can someone please confirm the vacuum line connection on the air box? I have the vacuum line that goes to the vacuum T connected to the top metal outlet on the airbox. There is a plastic nipple that seem to let air in freely. I vaguely remember breaking something around this area. Am I missing a line or is this ok?

My smog check failed with very high NOx. I realized after the smog test the vacuum line was completely loose. Can this be why NOx was 4 times the limit?

History:
- new radiator
- PCV redone
- P0455 large vacuum code. Now fixed after tightening various vacuum hose.
- Coolant temp in 190-210F range
- 210K miles

[abscate]

There should be another hard vacuum line that runs from the open nipple to the air door motor under the air cleaner

Excess air from the vacuum leak is unmetered, so your car runs lean, with high NOx emissions

[erikv11]

The airbox is missing line 6 from this thread viewtopic.php?t=65002

[jdw]

Thank you abscate and erikv11 for the quick responses. I've reintroduced line #6, I believe that line has been missing for years. Can I take it back for smog right away or give it time for the ECU to learn the new non-lean condition?

[850oldschool]

Your car may not be a '96, there's nothing like that on my '96.

[abscate]

You will have to clear codes. Then drive about 100 miles for the monitors to go ready before you can smog.

You might be allowed to pass smog with two monitors not ready, depends on your local smog rules where you inspect.

There are lots of threads on “readiness “ and “drive cycle” here for deeper understanding

[misha]

Your car may not be a '96, there's nothing like that on my '96.

Late '96 and all '97 n/a have this setup.

[erikv11]

Your car may not be a '96, there's nothing like that on my '96.

I've had two 96 850 NAs, they both have that line.

EDIT: Oops I missed misha's more thorough answer, right above mine here.

[jdw]

After installing line #6 with a rubber vacuum hose, I triggered a reset from the OBDII reader. No CELs where present before the reset.
To get the readiness checks to an acceptable level I performed two drive cycles (both starting with cold engine). In the middle of the second drive cycle, when idling for 60 secs, a P0410 check engine light came on. I haven't had that code in a long time. I've been reading on the Secondary Air Pump remedies.

• I believe my pump itself is ok, it runs when providing direct power. When disconnecting the hose to the SAS valve and direct power supplied, there is a powerful stream of air coming out of the hose. I'm not detecting any water in the pump.

• Smoke testing with home made device and glove over throttle is not showing any smoke. I realize some valves in system are closed

• In reference to whether line 6 should be present on my car, my left the factory January 1996. I am the original owner. I found the open nipple to the air door motor under the air cleaner as mentioned by abscate. After installing this line I noticed that the RPM drop, when the EVAP test activates during idling, was much more noticeable. It does not stall the engine.

What should be my next step?
1) SAS delete with diode in ECU. Will this prevent any readiness monitors?
2) replace all vacuum lines with silicone in case they are sub-par?
3) new SAS valve?
4) new O2 sensor (current one is 4 yrs old with less than 20K miles)

I have about 2 months till DMV deadline. Thank you.

[misha]

Remove negative battery cable for 15-30min in order to reset fuel trims,perform a re-learn procedure and see if code comes back.

Sometimes ecu gets wrong data and learn bad things after reset...so you need to reset it again...this time give it a "hard" reset.