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the engine isn't running cool, the temp is perfect.


The dash gauge and the ECU have different temperature senders. So the gauge may say fine, but if the ECU is getting a cold reading, it may put the engine in warm-up mode and pump in extra fuel. Just an guess at a possible cause, not saying this the the cause in your truck.


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I might wanna check out the trouble codes but i haven't done that bfore. does that work on all models?


Yes, details vary as noted.

And don't assume any part is OK, check everything you can. Is the catalytic converter clogged? How about the air filter and throttle body? Injector condition and fuel filter OK? Valves properly adjusted? Timing correct?