for a 99 ram 5.9 L and benefits of it?
Yes, you just ****** your engine, but you can fix it, Fill your gas tank up with water and let it run for a while, and ta da! Fixed!
It shouldn't, assuming the fuel was not contaminated with water or anything like that. Pretty much all modern engines use knock sensors that detect when knock or pinging occurs (can occur when lower octane fuel is used) and it will alter the spark plug firing timing to compensate for the quicker burn time of lower octane fuel to help protect the engine. Long term use of lower grade octane fuel than the engine is rated for can cause permanent damage to an engine but short term use is usually okay as long as you don't push the engine too hard. I would guess the warning lamp is another issue.
No, gas grade would not cause the check engine light to come one. BUT, the engine could just simply be in need of service. Some check engine lights come on at certain intervals to signal the need for maintenance which would include oil change, etc. The best thing to do it to take it in to have it checked. But, do not do so with an open check book. mechanics are crooks for the most part.
cold air intakes do exactly what the name implies, they get colder air into the intake by placing the filter in such a place where it gets air from the outside. a cold air intake, since the air that goes into the engine is cooler, increases performance and efficency they tend to give you 10-30 horsepower, depending on the application and 1-4 mpg better gas mileage, again depending on the application. depending on the brand, a good intake for your application would run you in between 200 and 300 dollars.
