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2003 Nissan Altima

115,000 miles. Runs terrible! Barely idles. Multiple misfires. Changed plugs, examined plug cores, checked PVC and changed air filter. No improvement. Finally poured a full can of Sea Foam 16 oz into gas tank. Ran it down interstate and drove for about 15 miles, at about 70-80 MPH, running bad, but then began to run smother. Got off interstate filled up tank with Shell (or other BRAND NAME fuel) and it has run better than ever! Searching internet help me find this possible solution. Full can was advised to be ok, ratio no greater than 4 oz per gallon of gas.

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what causes 2005 2.5l volvo to misfire and show code random multiple misfires i replaced plugs but no good

I would take it back and demand a refund. Could be the crank or cam sensors, an intake leak, faulty coil, or a list of other components.

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2005 Buick LeSabre missing badly

Is the check engine light on ? Do you own a scan tool ? not a code reader . Bad fuel or dirty fuel injector's .
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multiple cylinder misfire detected

Thank you for all the information. I don't see how you made it worse unless the injectors were not installed correctly. If you remove them you are suppose to replace the o-ring on each of them and oil them (the o-rings) before installing them. I would check the air filter and the CAT (for excessive back pressure. Also check the rest of the exhaust for damage. If a pipe is kinked or flattened it would need repair. Also GM's are known for some issues with there e-vap systems. You may want to check it out. The gas cap, charcoal canister, vacuum lines. Well good luck.

Apr 16, 2009 | 1997 Chevrolet Lumina

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