Letters: Clearing codes no guarantee for passing emissions test

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Q: I read that there’s a way to pass the emission test without fixing the car when the check engine light is on. The article said that you can have the codes read and then disconnect the battery for five minutes. Then you reconnect the battery and drive it immediately to the emission test facility. It said that since the emission test facility’s computer checks your car for codes and it won’t find any after this procedure, the car will pass. Do you think this will work? – George, Chicago

A: No. They check for more than just codes. When the codes are erased or cleared, so are the readiness monitors. Readiness monitors are tests that your car performs on itself during different modes of operation. Some readiness monitors take a significant amount of driving before they are completed.

In Illinois, 1996-2000 model year vehicles are rejected when more than two noncontinuous readiness monitors are not completed. Models dating from 2001 and beyond can’t have more than one noncontinuous monitor not completed.

If the check engine light is coming on due to an intermittent problem, and the battery is disconnected long enough to clear the codes, and the car has been driven long enough to complete the necessary readiness monitors without the check engine light being commanded on, then the car will pass.

Q: The service traction control light and ABS light keep coming on in my 2004 Pontiac Montana. This happens while driving along and sometimes when I’m braking. I have had the right side bearing and hub replaced about four times. The problem usually happens within three or four days after the repairs are made. What could be the problem? – Richard, e-mail

A: There could be a problem with one of the electrical terminals in the harness side of the wheel speed sensor connector. Disconnecting and reconnecting this sensor’s connector may provide a temporary or intermittent connection. The first step, though, is to have the trouble codes checked to see what circuit is affected. If there are any codes stored, a diagnostic procedure will need to be followed. If there are no codes stored, then the technician should carefully inspect all the wheel speed sensor electrical connections.

Q: I own a 2008 Nissan Altima. I purchased a replacement cabin air filter but I can’t find where it’s located in my car. I was told that you have to remove the glove box to replace it. So I removed the glove box but I couldn’t find the filter. Do you know if my car has one and where it’s located? – Bill, Oak Forest

A: According to the service information for your Altima, you do need to first remove the glove box assembly. Then you’ll have access to the cabin air filter’s cover, which has a tab that needs to be disengaged so the cover can be removed. Once the filter’s cover is removed you should see the edge of the filter and be able to replace it.

Questions for Ira Siegel? Call the Auto Advisor Hotline at (708) 633-6839 or e-mail ira.siegel.is@gmail.com. Siegel is an automotive instructor and an automotive service excellence-certified master auto technician.