Secondary Air: Diagnosing and Removal

**b.lee** · 05-08-2013, 10:07 AM

Is there anyway to test or check for a bad check valve?

**pajeff02** · 05-08-2013, 04:29 PM

With the hose disconnected from the valve start the engine. If the valve is bad, you will have exhaust blowing out the open end of the valve. You can disconnect both and see if there is a noticeable difference from left to right. Please note that the sound of the exhaust will be altered with the hose off the valve even if it is working properly. So do not reply upon sound alone in determining if the valve is good or bad. I have a set of diverter valves that may have been on our car for 1,000 miles or so -- would be happy to unload them with the stand pipes as well if you need them.

**initechpeter** · 05-08-2013, 05:40 PM

Awsome write up. I started this earlier today after work and can tell the difference with all the room under the hood. Makes changing plugs a snap on the pass. side now. Finished it up tomorrow.

**pajeff02** · 05-08-2013, 07:03 PM

My favorite was stashing the cruise control behind the PCM. Anything that cuts down on underhood clutter is a plus in my book.

**b.lee** · 05-09-2013, 06:25 AM

Thanks pajeff02!

**pajeff02** · 05-09-2013, 09:30 AM

No problem. Hope you get it figured out and fixed.

**Acslater** · 10-13-2013, 09:33 PM

I plan on doing this, as I am throwing a bad check valve code, and I know my MPG has taken a shit. The only concern I have is blocking off the line coming from the intake manifold, 01 is the year. And I know there is a nipple like connector for vacuum. I don't need to remove the intake to get to this do I? I can just plug it off where it connects to the diverter, what's the easiest, cleanest method?

**pajeff02** · 10-14-2013, 04:34 AM

Welcome to the site!

You can access everything easily including the vacuum source line which does need capped. The only exception is the bolt on the back of the driver's side head. The bolt retains a bracket on which the diverter valve assembly is mounted. If you are removing everything, you have to back this bolt off a couple of turns. Fortunately, the bracket is notched so the bolt does no have to be completely removed. There are also grounds located back there so make sure you do not disturb them.

**Acslater** · 10-14-2013, 05:49 PM

Thank you, so the vacuum line source is behind the intake I assume correct? Or can it be capped off on the actual hose itself going to the diverter? What is the best method to cap it off, and what should I get to do it.

**pajeff02** · 10-15-2013, 04:06 AM

You can buy a pack of vacuum caps at most parts stores. If you carefully trace the line you'll find that it comes from the back passenger side of the engine. Where you cap it really does not matter, just so long as it doesn't contact the exhaust or wear through and cause a vacuum leak down the road. I'd have to go back and look at the pics in this thread to remember what I did -- it's been a while.

**RV8D** · 06-27-2014, 05:52 AM

Thanks pajeff02 for this excellent thread, it helped me to successfully diagnose the P0140 code seen on my 2000 WS6. Which for the record was a clogged passenger side manifold tube.

**pajeff02** · 06-27-2014, 01:31 PM

No problem. That's what we're here for! I have a set of tubes and darn near brand new valves if you need any parts.

Welcome to the site!

**RV8D** · 06-30-2014, 04:33 AM

Originally Posted by pajeff02

No problem. That's what we're here for! I have a set of tubes and darn near brand new valves if you need any parts.

Welcome to the site!

Thanks for the welcome.

The same CEL came back on yesterday morning, I guess I was unable to clean the passenger side tube as well as I thought I did (those bends in the tube were making it tricky). PM me about those tubes and valves you have if you don't mind.

**pajeff02** · 06-30-2014, 04:23 PM

I'll have to retrieve them from our lower garage and will post a pic.

**pajeff02** · 06-30-2014, 05:59 PM

**RV8D** · 07-01-2014, 06:17 PM

PAjeff02, what are you letting them go for?

**pajeff02** · 07-01-2014, 06:32 PM

How about $35 shipped for the pair?

**RV8D** · 07-02-2014, 09:51 AM

Originally Posted by pajeff02

How about $35 shipped for the pair?

Sounds fair to me. Let's do it.

**pajeff02** · 07-02-2014, 07:10 PM

You do not have sufficient posts to PM me -- go ahead and shoot me an email with your name and address. I can mail them out to you Saturday as my schedule is cooked for tomorrow and Friday is a holiday. I assume they will fity in a flat rate box at the Post Office - if not, I'll find something at my office to box them in. I may have spare gaskets as well - if I do, I'll throw a set in the box.

**ws6Poncho** · 07-27-2014, 04:28 AM

I have been chasing a whining noise that comes and goes, no rhyme or reason, to the air pump. Instead of replacing the pump, I would rather remove the secondary air system and tune it out. Problem is, I live in New York State. Will the car pass inspection? Would love to hear from other New Yorkers on this.