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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29523
Experience:  GM Grand Master Technician 2007. 14 years experience.
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What if engine power is reduced and we can only go 20mph? We

Customer Question

What if engine power is reduced and we can only go 20mph? We stopped on the highway when the exhaust filter warning light came on and when we stoped the engine power reduced light came on.
Submitted: 2 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 2 years ago.

HI there, I am Cam. Can I get your first name pleasE? can you also tell me your year, model and make please? That seems to have been cut off.

Customer: replied 2 years ago.
2008 Chevy 2500 HD duramax. My name is Tiffany
Expert:  GM Tech (Cam) replied 2 years ago.

OK Tiffany, had you been driving at speed for some time before this happened or had you been idling and such?

Customer: replied 2 years ago.
Driving on the interstate.
Expert:  GM Tech (Cam) replied 2 years ago.

OK, so there is a fault in the system somewhere. For this to come on driving means it was not cleaning itself as you drove, and the only reason that would happen is a fault. Usually its the rear exhaust temperature sensor that fails. When it does, the system cannot monitor itself. I don't suppose you have a scan tool that we can confirm this is the issue with a code number?

Customer: replied 2 years ago.
No scan tool and it got back up to a 40 mph speed and now it has lost complete power and shut down and we are stalled in middle of road
Expert:  GM Tech (Cam) replied 2 years ago.

Boy that is not good. I am sorry to say that I don't think we can do much without a scanner. I suspect based on what you said that you will need the sensor then the shop will need to perform a service regeneration which is manually burning off the soot in the exhaust filter and restoring power. This can only be done with a scanner once the issue is fixed.