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Gary
Gary, GMC Technician
Category: GM
Satisfied Customers: 16654
Experience:  15 years gm master tech/15 years ASE master tech
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I have a 2004 Yukon XL. while driving I could not go over 60

Customer Question

I have a 2004 Yukon XL. while driving I could not go over 60 mph. the engine light came on. Than the speed went down to 10 mph, and it stalled repeatedly while trying to get to a safe location. I knew I was due for a full tune up. The mileage is 150,000. The spark plugs have now been changed. the throttle body has been checked and is great. The Mass Air Solenoid was replaced. Now, my mechanic is going to do a compression test on the right side of the engine, since the spark plugs on that side were in terrible shape.
He is still not getting power out of the engine. He is going to do a compression test on the right side cylinders. Is there anything else that can cause this problem?
Submitted: 1 year ago.
Category: GM
Expert:  Gary replied 1 year ago.

can you tell me the code numbers it is setting ?

Expert:  Gary replied 1 year ago.

this can be low compression or very common the cat converter for that bank of cylinders restricted or plugged

usually pulling out the front O2 sensor out of that bank before the cat converter and taking it for a quick ride and if the power comes back then the cat is bad