The Truck has an exhaust leak but runs fine other than when gassing it the truck is kind of sluggish and hesitates. The codes popped up about a month or two ago and I replaced O2 sensors (They looked damaged) and cleared codes and nothing the light came back. I am currently replacing spark plugs and wires to see if that helps but it doesn’t really idle ruff or misfire so I’m not sure if it’s an ignition problem, fuel problem or exhaust problem

 

Here is a list of issues that might be causing your problem:

• Mass Airflow Sensor (MAF) (you can clean it and see if that works)
• Defective Manifold Absolute Pressure Sensor (MAP)
• Defective Oxygen Sensor
• Defective Fuel Pressure Regulator
• Defective Coolant and/or Air Temperature Sensor
• Thermostat is stuck open
• Ignition Misfires
• Defective Throttle Position Sensor
• Defective or restricted fuel return line
• Defective Fuel Injectors

Hopefully one of these conditions will be found.

 

would any of these throw a code if it was bad and I had to replace fuel pump cause it went out now it still runs rich and is sputtering as if it has no gas. I may have air in the lines from having an empty tank and and empty lines since I also put in new filter.

 

Some of these issues would throw a code, yes. 02 sensors would throw a code(s). As for changing a fuel filter, I've done so with no issues on my 98 K-1500 no problems.

A dirty or bad MAF sensor may not throw a code, but my guesstimate is that that is not your issue. It's never a good idea to run low on fuel with an in-tank electric fuel pump, as the gasoline cools the fuel pump. No, a bad fuel pump wont throw a code on older pre-2005 Chevrolet's at all. I don't even know if they will on newer GM vehicles. Is it making the buzzing noise when you first turn the start/ ignition switch on? Might want to check the fuel pressure at the fuel pressure regulator.

 

I didn’t clarify I put in a new pump and filter and then the running rich code was still there but I also was sputtering drove to school today no problem starts up idling high but slows to normal I changed o2 sensors as well no help

 

I didn’t clarify I put in a new pump and filter and then the running rich code was still there but I also was sputtering drove to school today no problem starts up idling high but slows to normal I changed o2 sensors as well no help