Monthly Archives: April 2016

Cars Oxygen Sensor

If your car’s “Check Engine” light is glaring at you, it’s probably because the oxygen sensor is malfunctioning. That’s right, the oxygen sensor. It’s a little device that’s a mystery for most drivers but its misbehavior is the problem that most commonly triggers a Check Engine light, according to CarMD.com, which sells an automotive diagnostic tool and provides repair information. The oxygen sensor unseats the formerly most common Check Engine light culprit: a loose gas cap. There are fewer reports of that problem because savvy motorists have learned to fix it themselves and consumers now buy new cars with capless gas tanks.

But don’t despair. Replacing your car oxygen sensor will keep you from wasting money by burning extra gas, and the repair isn’t horribly expensive. We know this firsthand. We had to replace the O2 sensor on our 1996 Lexus ES 300, the subject of our Debt-Free Car project, and it wasn’t as much of a hassle or expense as we had feared.

After the dreaded Check Engine light appeared in our Lexus, we plugged the CarMD device into the car’s computer to read the error code. In our case, the code was P0135, which meant that the oxygen sensor in “bank 1” was malfunctioning. It was surprising to learn that something was wrong with the car, since it still seemed to be running fine.

Even though a car seems to be behaving normally, a faulty oxygen sensor will cause the engine to start “gulping down gas,” says Kristin Brocoff, director of corporate communications for CarMD.com. She says this problem can cause up to a 40 percent reduction in fuel economy. Sure enough, when we checked our fuel record for the driving we did while the Check Engine light was on, our mpg had taken a hit.

The oxygen sensor, developed in the early 1980s, is an essential part of the car’s emissions control system, says John Nielsen, director of engineering and repair for the American Automobile Association (AAA). The sensor is about the size and shape of a spark plug and protrudes into the car engine’s exhaust stream. It determines if there is a lot or a little oxygen in the exhaust, so the engine can make adjustments to the amount of fuel being used in the engine to run at maximum efficiency.

Oxygen sensors in older cars fail for a variety of reasons, according to Bosch, a leading manufacturer of auto components. In some cases, sensors are fouled by gasoline additives or oil from worn engines. Newer oxygen sensors can last 100,000 miles if conditions are right, but often problems occur sooner.

After we plugged CarMD’s diagnostic device into the Lexus’ onboard computer port, we connected it to our desktop computer. It accessed a database of information about this engine code and how to have it repaired. Among other things, the report included an average estimate just to buy a new oxygen sensor: $168.82.

At the first sight of a Check Engine light, most owners of new cars that are still under the factory warranty would simply make a beeline for the dealership’s service bay. But car owners on a budget might want to go the do-it-yourself diagnosis route to save money. By using the CarMD device, or any engine code reader, drivers can learn what the problem is, and the skill level required to fix it, before attempting the task.

Modern cars have two to four oxygen sensors, Nielsen says. A V6 engine, such as the one in our Lexus, has one sensor in each exhaust manifold and one after the catalytic converter. The sensors simply screw into place, but reaching them can be a problem for do-it-yourselfers. Additionally, since the exhaust subjects the sensor to extreme heat, it can “seize” (become frozen in place) and be tough to unscrew. A new sensor comes with anti-seize compound to apply to the threads, but the compound should never be put on the sensor itself.

Nielsen says that while a code reader might indicate that the problem is the car oxygen sensor, there are other problems that can trigger the identical code — a disconnected vacuum hose will do it, for example.

As a first step, a car owner can look under the hood to see if there are any wires or hoses disconnected, Nielsen says. In some cases, a wire leading to the oxygen sensor could be broken or burned out. If nothing obvious is visibly awry, it’s time to go to what Nielsen calls “a trusted mechanic.” Reputable garages use an expensive diagnostic machine called a scan tool — not to be confused with an inexpensive code reader — that can watch the operation of the engine in real time and see if the oxygen sensor is actually the problem.

“Most motorists would be well served to find a shop that they trust and take their car there for all oil changes and tire rotations,” Nielsen suggests. “Then, when they have a problem with something like an oxygen sensor, they trust what the mechanic is saying rather than thinking that they’re trying to rip you off.”

In our case, we learned that the faulty O2 sensor was in the rear of the engine and difficult to reach, so the fix seemed above our skill level. Instead, we took the Lexus to Overseas Garage, in Long Beach, California. There, the mechanic told us that the new sensor would cost $117, plus $144 in labor for a total of $261. This was close to the $246 average cost cited by CarMD’s Brocoff.

While many people opt to simply ignore “Check Engine” lights, Brocoff says this can cause bigger, more costly problems later. “So the problem you could have fixed for a few hundred dollars turns into a repair of the catalytic converter, which would be over a thousand.”

Driving back from the garage, it was a relief not to stare at the glowing check engine light. This made us realize that fixing such a problem provides another benefit: peace of mind.

Tips to Find a Good Car Mechanic

We hear it all the time: “Where can I find a good car mechanic?” In the past, word of mouth was probably the best way to find an auto repair shop that would do the job right and charge a fair price. But now, a good mechanic might be only a few mouse clicks or touchscreen taps away.

Crowdsourced review sites have greatly simplified the search. Here are a few tips on how to work these sites to find a good car mechanic in your area. Keep in mind that this isn’t an exact science. Sometimes a highly rated shop might disappoint, but at least you can tilt the odds in your favor.

Yelp
Yelp.com describes itself as a site that “connects people with great businesses,” whether that’s a hot new restaurant or a top-notch dentist. And, luckily for car owners, it also has auto repair reviews. The site is free and has a mobile version, plus apps for Android and Apple mobile devices.

We’ve had good experiences with Yelp recommendations as we looked for a mechanic to work on Edmunds’ long-term 1996 Lexus ES 300, which is the subject of our Debt-Free Car Project. With our new long-term vehicles, we tend to use dealerships exclusively. But because containing costs is important for the Lexus project, we’ve used Yelp four times to locate independent mechanics. Of the four, we would go back to three of them. We’ve found Yelp to be the most useful site, thanks to its review volume and convenience.

Here are a few tips to help you narrow down your mechanic search. Type “auto repair” into the search field and enter your ZIP code. You can filter the results based on distance, most reviewed and highest rated. The goal should be to find a place that strikes a balance between a good rating and a substantial number of reviews. For example, a place may have a glowing review, but if it’s the only review, that customer’s experience might not be the same as yours. Or worse, it could be a misleading review from an employee or business owner.

Yelp has an algorithm that helps it spot misleading reviews, but sometimes they can slip by undetected. That’s why it is important not to put too much stock in one review. Instead, see what patterns emerge after you’ve read numerous reviews. Look for reviews that are specific and give plenty of details about the users’ experiences.

Sometimes, the owner of an establishment will reply to a review. This response can either be a thank you to someone for a good review or a defense or apology if the review was a negative one. Either way, we consider a thoughtful reply a good sign — particularly in response to a negative review. It shows that the business cares about its reputation.

Angie’s List
Angie’s List prides itself on having a thorough vetting process for its reviews, which cover everything from automotive listings to home repair and even wedding planning. In a search we did for our area, Angie’s List provided a number of repair shops nearby, but we found the volume of reviews lacking when compared to Yelp. For example, one repair shop we used for the Lexus had just one review on Angie’s List, and it was from 2008. The same shop had 22 reviews on Yelp, with the most recent one being less than a month old.

The small number of reviews on Angie’s List can be both a good and a bad thing. On one hand, the chance of a falsified review drops considerably, since the site requires a paid membership to access the site and post a review. But at the same time, it is hard to get a feel for a shop that has very little feedback.

Google
Google’s enormous database will yield the greatest number of search results, but they may require some extra filtering to be useful. Type “auto repair near (your ZIP code)” into the search field. Ignore the sponsored ads at the top of the page. The repair shops will appear about halfway down the page, with their address to the right of their listing. Google has its own review and scoring system. Approach these as you would Yelp reviews.

What is the effect of Cheap Gas

Gasoline is expensive and you’re looking for every way possible to save money at the pump. You already shy away from premium fuel, knowing that your car doesn’t require it. You’d like to save a few pennies per gallon more by going to an off-brand gas station. But you can’t get rid of the nagging fear: Is the cheap gas going to damage your car’s engine?

Edmunds.com put this question to experts in several fields, including an automotive engineer at a major carmaker, gasoline manufacturers and two engineers with the American Automobile Association (AAA). It boils down to this: You can stop worrying about cheap gas. You’re unlikely to hurt your car by using it.

Because of the advances in engine technology, a car’s onboard computer is able to adjust for the inevitable variations in fuel, so most drivers won’t notice a drop off in performance between different brands of fuel, from the most additive-rich gas sold by the major brands to the bare-bones stuff at your corner quickie mart.

Still, spending a few extra pennies per gallon might provide peace of mind to someone who just purchased a new car and wants to keep it as long as possible. People with older cars might not be as concerned about their engine’s longevity. They can buy the less expensive gas and still be OK.

Steve Mazor, chief automotive engineer with the Automobile Club of Southern California, summed it up this way: “Buy the cheapest gas that is closest to you.”

Recipes for Performance — at a Price
But this doesn’t mean that all gas is the same, even though it starts out that way. The fuel from different filling stations comes from a common source: the “base gas” from a refinery. Workers there mix additives mandated by the Environmental Protection Agency into the base gas in order to clean a car’s engine and reduce emissions. Then, the different gas companies — both off-brand and major brands — put their own additive packages in the gas to further boost both cleaning and performance.

A key difference is that the major brands put more additives in their gas and claim to have some secret ingredients. This extra shot of additives provides an additional level of cleaning and protection for your engine.

But is this extra helping of additives, which jacks up the price, really necessary? And, if you don’t use more expensive, extra-additive gas, how soon will your engine’s performance suffer?

“It’s not like any of the fuels are totally junk,” says John Nielsen, director of engineering and repair for the AAA. “If you buy gas from Bob’s Bargain Basement gas station because that’s all that’s available, it won’t hurt your car,” he says.

The real difference is the amount of additives that are in the gas, Nielsen says. More additives essentially afford more protection — but they also cost more.

Some automakers and oil companies believe that the amount of government-required additives isn’t enough to protect engines. They have created a Top Tier gasoline designation. It means that those gasoline brands sell fuels that provide more and better additives.

Nielsen recommends that drivers look in their car’s owner’s manual to see what the carmaker recommends and, when possible, follow that guideline. People who are still concerned about gasoline quality can ask a specific oil company if it has performed independent testing to substantiate its claims.

Selling the Secret Sauce in Gasoline
The major oil companies spend millions of dollars convincing buyers that their gas is superior by creating ads that feature smiling cartoon cars, lab-coated nerds and sooty engine valves. Buy Shell’s nitrogen-enriched gas, for instance, and you won’t get a buildup of “gunk” in your engine, company advertising promises.

Is all this just a marketing gimmick?

“I am a Ph.D. chemist, a nerdy guy who wears a white coat,” says Jim Macias, Shell Oil Company’s fuels marketing manager. “We really believe there are differences in fuels. We can see it, feel it and measure it.”

Macias says the gunk caused by fuels with insufficient additives can foul fuel injectors and even trigger “Check Engine” lights in as few as 10,000 miles.

But not everyone is keen to talk about gasoline quality and whether additives really make the difference.

Edmunds sought comment from one well-known seller of low-price gas: Arco. Arco also often finds itself targeted as being a lower-quality product. BP, Arco’s parent company, did not respond to Edmunds’ interview request.

The American Petroleum Institute provided background comments about fuel additives and promised to provide an expert for an interview. The API spokesman never called back.

Finally, Southwest Research Institute in San Antonio, an independent, nonprofit testing facility, also declined to comment on the question of gasoline quality.

The Skeptics and Their Tests
The Auto Club’s Mazor was more forthcoming, and has some interesting results from a blind test he did on three samples of gasoline from both major and independent gas stations.

“We tested emissions, fuel economy and performance and we could not tell the difference,” he says.

Mazor believes that the driving public has outdated notions about gas. Twenty years ago, only premium fuelhad detergents in it. Back then, it was beneficial to occasionally buy a tank of high-test gas to clean the engine. Then, he says, “regulations were very lax and there was little enforcement. But all that has changed.”

Likewise, Randy Stephens, chief engineer for Toyota’s Avalon, isn’t wholly convinced by the claims of engine protection afforded by higher-priced gas. He says fuel experts at his company study the effects of different brands of gas on the Toyota engines. Automotive engineers disassemble engines after 10,000 miles of running them on different brands of gas to see if there is a difference.