Question about 2002 Jeep Grand Cherokee

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Engine Light My check engine light comes on when I use certain types of gas. Is there an octane that I am supposed to be using? Am I hurting something by using different blends?

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I had the same problem. I noticed a small beak in the rubber gasket on the gas cap. I bought a new gas cap and the problem went away.

Posted on Nov 02, 2008

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What is the code? Could simply be a loose gas cap setting the light off. If the light goes off after several engine run cycles, it's not a consistent problem. Blends may affect performance but shouldn't hurt the vehicle if you are using the correct octane. Your owner's manual defines the required octane.
Some parts stores scan your vehicle for free in hopes you'll buy parts to correct whatever the code is. Be careful as codes mean more than 1 thing usually. Get the code from the store and post from there.

Posted on Jun 11, 2008


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I put bad gas in 2004 lincoln aviator

The fuel your using, has nothing to do with the problem,
is the gas cap on properly

What logic, tells you adding octane booster would repair a vehicle,
& how would an additive turn off a light & do so quicker.

There are no products in an auto parts store in a bottle, that are ever needed in any vehicle,if they were, they would be listed in your owners

You should have had it checked for codes & looked them up or given them to us to look up

It would seen you have an EVAP System issue you need diagnosed.

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My 2003 S-10 with 48,000 had the check engine light come on today. I just recently bought the truck from an elderly lady that stated she has never had a problem with the truck. I put 85 Octane gas into...

The difference in fuel type won't turn the check engine light out. You may be on the right track with the new fuel cap, they are very common to set an EVAP code, usually P0442 for a small leak (such as a loose or leaking gas cap). The other problem they are known for is code P0128 for a faulty thermostat, opening too soon. It's still best to have it scanned at a large parts retailer, usually for free, then diagnose the actual trouble code rather than just the symptoms. There are literally 1500 trouble codes for your vehicle alone.

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Can to high of octane cause the check engine light to come on? I just bought a 2001 VW Golf and when I filled it up I put 91 octane in it then the engine light came on. Ive tryed the gas cap but light...

Wrong octane could very well cause the check light to come on as well as a million other reasons. But make sure the fuel cap is on tight sometimes that can trigger a code. If you still have the light on after 50 miles I would have the OBDII system read to get the codes of why the check engine light is on. Elevation should have no effect.

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I have 2001 V6 Mustang. I was keep putting 87 octan gas but just recently I changed ontan gas from 87 to 91. Is it going to hurt? I shouldn t change it?

No it will not hurt and there is no reason to switch to a higher octane gasoline with this engine. Certain engines in Corvette, Cadillac, etc with special combustion chambers utilizing different types of metal for performance need higher octane gasoline. Your v6 does not. If you hear knocking, have your valves checked and make sure you oil pressure is good. If you switched for no reason, switch back and save yourself $$$

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1 Answer

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Could be one of three things:

If the check engine light is coming on intermittently, it could be your gas. You should be using 91+ Octane Gasoline (put some octane boost to see if it smoothes out, it's about $4.00). You should be putting in Chevron/Shell/76 gasoline, not the ARCO/AM-PM gasoline. The top tier gas has additional cleaners.

Could be a bad coil not triggering one of the spark plugs.

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Check engine light is on.... The weather is 9 degrees. Does this cause light to come on?

weather should has no effect on the service engine lights. service engine light could mean many things wrong. O2 sensor is common problems triggering the lights. most people don't realized that unit need to be replace every 50-75k miles. it does not hurt to drive it, however you may notice a change in the performance and gas mileage. first try to run on 93+ octane for awhile on one full tank and see if that light will stay off. Most gas are now mixed with 10-15% ethanol causing O2 to sense incorrectly.

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Engine check light is on what i can i do

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2003 stype jaguar chek engine light went after low octane gas was put in

thats because of spark knock which can damage the engine(pinging). if you have not hurt any thing, immediatly put in some octane booster and then premium fuel. also keep your foot out of it to keep the load off the engine to reduce pinging until the yucky gas is gone. the light should go out on its own when the correct octane fuel is in use. dont use anything lower than 91 octane in it or ull b sorry...

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1 Answer

Will 87 octane make my check engine light come on in my 03 t.b when i put fuel injector cleaner in it the light goes out

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