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The_Bayfield_Bu's avatar
The_Bayfield_Bu
Explorer
Mar 23, 2015

Need advice on Chevy 8.1 Vortec engine (2003)

We have experienced loss of power going up long steep grades. and the engine light on.
3 times. After the second time , a truck service repair said the 02 sensor (bank 1 & 2) probably came on due to the long grade and elevation chg. He cleared it and we had him do an oil chg. & fuel filter. Same thing happened now again on our way to Moab. Loss of power and light on.
Should we take a chance and have a truck/RV service place replace the sensors or is this better left to qualified Chevy techs?

I've read that we should have the exhaust manifold gaskets checked as well in case that caused the sensor problem.
Class A

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  • Golden_HVAC's avatar
    Golden_HVAC
    Explorer
    Mar 23, 2015
    It only takes a few minutes to change the CO sensor, and probably they did not have yours in stock in a small town like Moab.

    Have you been filling up with 'regular' gas? IT can be 85 octane in Moab area, and anyplace that is over 5,000' elevation. Try filling with (gulp) 91 octane or higher and see what that does for you. It might be that the knock sensor was hearing something and went to the low power mode because of the low octane gas.

    Higher octane fuel will provide much better MPG. 85 octane might be fine in Denver, but as you leave the higher elevations, and as you try to climb a steep mountain, you really do need 87 octane or higher fuel.

    It only took me a few minutes to change my O2 sensor in my Dodge van. the one on my motorhome was really easy, and all I needed was a 7/8" wrench. The Dodge required a special tool, Napa has a couple of designs that cost only $6.95. Ask at the counter.

    Good luck!

    Fred.

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