Spark plug replacement recommendation on all Lexus models.
hello everyone i changed the plugs in my 96 es and after i changed them my engine shakes a bit it didnt do that before what did i do wrong
So go back and replace them all again using much more care. Use the exact DENSO or NGK plugs listed in your owners manual instead of imitations or substitutions. Changing spark plugs is serious business.

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Example: Changing spark plugs every 60-90,000 miles and engine oil every 3000-5000 miles helps minimize engine wear and maintain optimum fuel economy which in turn extends the life expectancy of all the complicated and expensive emission and ignition system components far beyond 150,000 miles.
Owners who extend preventive maintenance service intervals way out to the limit commonly end up with a car at around 150,000 miles that frequently needs all kinds of expensive things replaced and such owners may end up deciding the car is not worth keeping because of all the cost and hassel to replace all the things that keep going wrong.
A key point in gcrim21's service manager quote is "not...changing the plugs before 120,000 miles unless I started having problems with them ". If your engine is running rough or fuel economy is suffering, of course the plugs and other ignition and fuel components should be looked at and/or changed.
But I am not aware of any emission or ignition system components, on a well-running 90K engine w/original plugs, that would be deteriorating at an accelerated rate just because the plugs have not yet been replaced.
In this way like new levels of engine performance, fuel economy and exhaust emissions. are maintained for many hundreds of thousands of miles. Electrical loads on the spark generating componets of the ignition system are kept at minimal levels which prolongs their life. The load of unburned hydrocarbons in the exhaust stream is also kept at minimal levels which prolongs emmission system component life.
Of course, like I said before this is all irrevalent to the owner who plans to sell or trade their car
at or before 150,000 miles.
THanks











