my service enjine light say something is wrong with egr valve and 02 sensor, would this be why I am using so much oil.
Nope. These can affect idling, emissions, and gas mileage, but not oil use.
How many miles does the truck have?
Any other symptoms?
How’s the maintenance been?
truck has 140,000 miles, uses oil, stalls out at stops, rough idle, has a sound like a low octane knock at acceration
Stalling at stops and rough idle could quite possibly be due to the EGR valve being stuck open. But fixing the EGR system (if it is broken) won’t do anything about the oil usage.
The EGR valve and the O2 sensor could easily be causing the stalling and rough idle, along with other overdue maintenance if there is any. The oil burning is a whole seperate issue.
Honestly, I think I’d want to do a compression test on this truck before dumping too much money into it.
It could be the other way around. Your parts may be damaged because of the excess oil use.
Excellent point…and I’d bet you’re right.
I’m embarassed that I didn’t think of that.
To the OP: excess oil burning can and often does leave carbon deposits on the EGR valve, gumming it up, and coat the surface of the O2 sensor, rendering it unable to send a proper signal.