Consider how dirt affects sensor output and how you can avoid fault codes leading you by the nose in your diagnosis procedures.
Oxygen (O2/Lambda) sensor replacement tips Such sensors are vehicle specific, which emphasises why a replacement part must share the same specifications as that fitted at the factory. Due to their location, constant contact with corrosive gases and the extremely high-temperature exposure, corrosion tends to make removal extremely tricky. Therefore, invest in special tools, such as a tube spanner. While this can prevent damage to the sensor, it can also reduce the risk of personal injury. Once you have removed the old sensor, check that the threads in the exhaust pipe are clean and serviceable. NGK told AT that all sensors, sold under its NTK brand, have an anti-seize grease applied to its threads but warns that alternative greases can damage the sensor. Tighten the sensor to the recommended torque; overtightening can damage the sensor body, as well as the threads. The torque is specified to ensure not only a good seal but also an adequate electrical earth, where needed. Check the multiplug for physical damage and corrosion too, prior to connecting-up the main loom and routing the wiring in such a way that it cannot be damaged by heat.
Ignition: Avoiding trouble by keeping clean While contemplating the meaning of life, Rob Marshall finds that dirt is a significant factor that influences ignition system longevity but he also finds that technician attitudes also play vital roles.
Like all parts of a motorcar, engine management sensors have a finite life. While they can fail suddenly, old parts on old and high mileage cars are likely to be past their best. While the rate of deterioration may not be sufficient to trigger an Engine Management Light (EML), they might not be working at their absolute optimum. Working on this basis, if the customer complains of erratic running, or a noticeable fall in fuel efficiency, then further diagnosis into sensor output would be a good idea before annoying the customer and 'firing the parts cannon', to coin a Dilloneon phrase.
A dirty state of mind
While cleaning can restore some sensors, consider whether the labour charges involved eclipse those of replacing the part. Should you decide to clean a sensor, research how you can do it and which product to use. For example, while hot wire MAF sensors tend to have their own built-in cleaning feature
IGNITION
Contamination is a major threat to sensor accuracy. With oil residue and exhaust gases passing through the inlet manifold, it is unsurprising that turbo boost and air temperature sensors, for example, can become clogged, which might send inaccurate readings back to the engine management system.
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