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Date:         Sun, 17 Mar 2013 02:18:52 -0400
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: Calif. Smog Fail and Catalytic Converter
Comments: To: Steve Williams <sbw@SBW.ORG>
In-Reply-To:  <201303161625.r2GGP3E54001@sbw.org>
Content-Type: text/plain; charset="US-ASCII"

A failed O2 sensor can destroy a cat. However the Cat and O2 sensor failing together is usually due to a common cause. O2 sensors can also be fouled from the outside. There was a deflector shield that I bet is missing. Typical causes of both the O2 sensor and cat failing are overheating, oil carry over from over filling and oil additives. Antifreeze making its way into the exhaust will also make short work of the Cat and O2 sensor.

Your pretest results defiantly indicate a bad Cat. The pre-test CO reading indicates a properly working O2 Sensor but the Cat did not reduce it.

While the after Cat readings passed you should note that the NOx reading is still high. Either the Cat is struggling to do the job or you have something else going on. Since you have a modified engine there is probably increased compression and you may also have the ignition timing over advanced. From experience when we had the dyno tests even things like oversized tire presented NOx challenges especially with the automatics.

What you want to do is have the emissions tested periodically using the port before the Cat. This will tell you what the engine is actually doing and then after the Cat will tell you how well it is working.

Dennis

-----Original Message----- From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Steve Williams Sent: Saturday, March 16, 2013 12:24 PM To: vanagon@GERRY.VANAGON.COM Subject: Calif. Smog Fail and Catalytic Converter

On 2/16, I wrote about a fuel leak in my '84 Westy that led to replacing the fuel lines and upgrading the aluminum injector manifolds. Nice to have that fixed.

The next day, I renewed the registration on-line without even noticing that it required a smog check. Every two years here in California, I think.

The smog check led to a new catalytic converter, but first some background.

GoWesty installed a 2.3L waterboxer in 2009, four years ago. At that time, they installed a later-model cooling system and replaced the muffler and catalytic converter. But they kept the stock air and fuel system and engine electronics.

Two years later, with 31,500 miles on the new engine, I stopped at GoWesty on my way from the S.F. Bay Area to L.A., in part to have them set up the engine to ensure it passed the smog test. At that time, I believed this installation requires some special knack that GoWesty would provide. (I now think it's not that hard, as I'll explain.)

They tuned the engine and did some other work, and recommended Smitty's around the corner, where it passed the smog check just fine.

At the same time, GoWesty found a slight exhaust leak blowing on the water pump, which was leaking again. But I needed to get to L.A. for the weekend, and the leaks weren't urgent, so we agreed it'd be OK for me to drive to L.A. for the weekend and return Monday.

On the way to L.A. and back, I was surprised to see the MPG going down and down! Arriving back in Los Osos, I filled the tank and calculated 12.9 MPG, down from an average of around 19.

http://www.fuelly.com/driver/sbw/vanagon/log/1427188

GoWesty found the O2 sensor had failed, apparently just after the smog check. Seems an unlikely coincidence, but, whatever. The MPG went right back up to 17.8, and ten days later it turned in 20.5 MPG over a 200-mile trip. Problem solved.

This month, when I realized a smog test was required, I phoned Peninsula Automotive in Campbell to ask for a recommendation of a test station. (I once went to a test station who couldn't figure out how to test a Vanagon, so I like to go where they see Vanagons all the time.)

http://www.peninsulaautomotive.com/

Peninsula recommended Accurate Smog Check just across the freeway. I drove down there after work on March 1 for a pre-test. They were very efficient and friendly. They charged $30 for the pre-test.

http://www.accuratesmogcheck.com/

At this point, I had 43,650 miles on the 2.3L engine. The pre-test failed due to high NO. This PDF has both the pre-test and the final test last week:

http://sbw.org/westysmog2013.pdf

Accurate said it looked like the engine tuning was dialed in just right, but the catalytic converter was shot. I drove over to Peninsula and showed them the report, and they concurred that a new cat was needed.

I was surprised, because I thought cats lasted longer. Four years and 43,650 miles? I don't actually know. Anyway, they said a failed O2 sensor can quickly cause early failure of a cat, so maybe that was it.

I was also surprised the other numbers were so good, because of my impression that the tuning is tricky with the modified engine. But that doesn't seem to be such a problem. The last tune-up was by Van Cafe in Santa Cruz last October, after they found the engine was running leaner than they prefer. I really liked the way it ran after that tune-up: No more pinging going over the mountain on Highway 17 at full throttle, and the MPG wasn't affected. And six months later, the other smog numbers were right where they should be.

Still, I didn't want to have Peninsula install a new cat without a second (third?) opinion, so I emailed the report to Chris Myers at GoWesty and asked him whether he agreed a new cat was needed and whether the failed O2 sensor may be responsible.

Chris replied quickly to say yes, he agreed a cat was needed. He didn't directly answer about the O2 sensor, but he did say, "The new cats sold now have more platinum and can control NO better." "New" since mine was installed in 2009, I assume. Chris pointed out their price for the cat, $260 (plus about $15 shipping) including gaskets and hardware. Their product page includes some commentary on the quality of cats:

http://www.gowesty.com/ec_view_details.php?id=23533

Peninsula also said cats sold today are better than a few years ago.

Last week, I took the van to Peninsula to install the new cat. They charged $325 for the cat, gaskets, and hardware. I try not to quibble about price differences.

Peninsula finished the work quickly, and I drove back over to Accurate to repeat the test. This time, it passed easily. They charged $65.

(In the two weeks between tests, Accurate had moved one door down Curtner Avenue to a new, bigger facility. Apparently they've been working on the move for almost a year!)

Like the work on the fuel leak, I learned a few things from this experience. It has been a shock to spend all this money on the Westy suddenly, but it gives me peace of mind to know my escape pod is ready for the next earthquake or financial disaster, or just a sudden need to chuck it all and get out of town.


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