2014 GMC sierra 5.3l fuel and emissions issues

mbalbritton

mbalbritton

#@$%!
Joined
Mar 22, 2005
Location
Lakeland, FL
As stated in a previous tech post, I’ve had cat converter issues on both banks. I still haven’t resolved that issue. I had a theory that was based around an open failed thermostat that ran the engine cooler and thus leaner that cause dirty cats. But it was just a thought.

Recent new developments are after sitting a for a few hours I will have an extended start. It will take 2-3x more cranking to start. If I just kick it he ignition on for a second and let the fuel pump prime, it cranks fine. So it’s Laing fuel pressure.

Also noticed that when starting up, there’s a warning on the dash that says to service the Stabilitrac system. Looked that up and one of the issues could be fuel delivery, among many other things.

I have 180k miles on it and have never serviced the fuel system. I’m really at the point that I’m about to just take it somewhere and say diagnose tha stabilitrac issue, replace the fuel pump, pull the injectors and clean or replace them and let’s see what happens. If I have to replace the cats two, I’m probably pushing in the neighborhood of $4-$5k to do all this I bet. And I need new tires to top it off.

Before I go that route, anyone have thoughts on stabilitrac and my fuel and emissions issues. Could I just be looking at a whole bunch of shit going wrong or is this symptomatic of a single issue somewhere in the system?
 
I had a 2014 Chevy 1500 w/Ecotec 5.3 and it crapped the cats at about 100k. Was after a bad tank of gas went in it, after filling it immediately started running like crap, lots of stumbles. I think there was a lot of water in the fuel. You may be having issues with crap fuel as well with the recent cranking issue. When it got super cold about a month ago my wife's vehicle refused to start after a lot of long cranking; when the issue popped up I remembered that the day prior I started it and moved it about 15' to clear some snow and turned it right off so it probably pulled water at the bottom of the tank into the fuel line and then when it got really cold it froze in the line because the vehicle acted like it did not have fuel to start. After a lot of cranking and help from a second battery it finally coughed itself back to life and is fine now. I put Seafoam in the tank and topped it up with fuel from another station.

Good diagnostic info on P0451 for these here: 2014 Silverado P0451 Code - Evaporative Emission System Pressure Sensor
 
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