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  1. #1

    Default Power loss in 1st gear...2005 Chevy Silverado...Please help...

    Hi all, new to the site, my name is Bill and I own a 2005 Chevy Silverado extended cab. The truck has been experiencing some power loss in first gear, just unresponsive sometimes when you mash the gas, it's like the gear doesn't engage or something, and the tach doesn't rev up or red-line when this happens. We have had multiple diagnostic tests done on the vehicle, and have heard everything from spark plugs and spark plug wires to a bad catalitic converter. At this point I do not know what to do...I am considering changing all the plugs and wires, but if I don't need to, I sure would like to know. This doesn't happen every time the vehicle is driven, just from time to time...if anyone could offer any help or suggestions, thanks in advance, it's greatly appreciated...

  2. #2


    Hi Bill, if the plugs, or plug wires were bad, the check engine light should be on, in fact, it should be flashing.

    Your description is that of a mis-fire, but the CEL should be on. Cats, on the other hand, do not always bring on the CEL when they plug. How does the truck act when on the highway, driving at 60 mph?

    '09 Avalanche LTZ - Black
    '05 Envoy XL (sold)

  3. #3


    Hello Ray, and thanks for your help, by the way...the CEL has been coming on and off now for quite a while. Last time we had a diagnostic, the guy actually told us the machine was reading a misfire, his exact, the CEL doesn't really flash though, just comes on sometimes and then goes off. Guy told us that after he did a diagnostic, the light would go off, and it did, but then it came back on again after a short time and has remained on. As far as on the highway at 60, the truck seems fine, really other than just taking off initially, the truck seems to not have this problem any other time. I'm just not sure how to proceed next. Once again, thanks for your help and taking time to help someone, who, while maybe a bit "inclined", is clearly not a mechanic, LOL...I'm quite confident I can fix whatever the issue may be on my own, save the cat converter...I appreciate your help, buddy!

  4. #4

    Join Date
    Sep 2010
    everett, massachusetts


    since this is intermittent and a 2005 the TAC is a good guess on the cause of the reduced power mode. when the PCM sees that the response from the TAC is NOT what is to be expected the engine will not produce any real power . usually 20 MPH max.

    you should however get a DTC when this occurs. so get the specific DTC to determine if this is the failure.

    problem : on hitting the throttle no acceleration !

  5. #5


    But @j cat, won't the TAC light the reduced power alarm and throw a code?

    The OP is getting a CEL, but one that indicates a mis-fire.

    @Birdman22770, Bill, do you know the code being generated? If unknown, lots of parts store will check the code for you.

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