Auto Repair Phoenix


Johnston’s is your repair shop for emissions testing in Phoenix. More often than not, emissions tests are considered a procedure that drivers are coerced by the state to go through occasionally. Though this is often the extent of the thought that is put into automotive emissions, it is important to remember exactly why this procedure is required by the state of Arizona.

If your vehicle is in good working order it will have no troubles passing the emissions test. A failing test score means that there is something going wrong with your vehicle which needs fixing before you will be given a passing score.

exhaust emissions test phoenixThe technicians at Johnston’s excel in troubleshooting your emissions problems and providing quick, affordable solutions for emissions test failure. Here are just a few reasons your vehicle may not achieve a passing emissions score.

Dirty Spark Plugs - your spark plugs are what initiate the small explosions that keep your vehicle moving forward. Old or dirty spark plugs may cause a misfire, which causes the vehicle’s exhaust to register as "rich". Changing out your spark plugs will eliminate this issue and lead to higher fuel economy.

Fuel and Air Filters - the fuel and air filters in your vehicle are there to ensure that the correct mix of air and fuel make it into the combustion chamber. If one of these becomes clogged or too dirty, not enough of either, or too much of one will contribute to a failing score.

Oil Change - Dirty engine oil contains a high concentration of Hydrocarbons. This will make your emissions results come back as too rich and you will fail the test. Changing your Oil every 3-5,000 miles will help your engine live longer and will contribute to a passing score.

Inflated Tires - Checking your tire pressure before going in for testing is always a good idea. Underinflated tires will cause your engine to work harder to maintain testing speeds and may affect your score.

it is a good idea to get a tune up before going through an emissions test. If you are unsure that your vehicle will achieve a passing score, ask us about our pre-test option and we will explain the process to you.

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