Just an FYI: No need to worry about running low on fuel. The idea that the fuel pump will overheat is a myth. The fuel return line discharges fuel directly into the well that the fuel pump is housed in. When the engine is running, the fuel pump is completely submerged in fuel, it won't overheat.

If you suspect a fuel pressure issue, check it, along with leakdown, it's free. If the check engine light is on, and there is a DTC relating to the EGR valve, follow the proper flow chart, diagnose & repair it. If there is no DTC in memory for the EGR valve, it's fine, leave it alone.

 

Checked the codes last night and I have the common P0420, should I follow the steps in the "P0420 Explained" thread first?

Thanks for the info about the fuel pump I kept seeing it on here when I first had the issues so I was just trying to be safe.

I had a shop do the fuel pump, I might take it back there first to see what they say.

 

My cat is rattling around, it sounds like little pieces are broken are rattling around in there, I think that's most likely the issue here?

 

If you bang on it with your fist, and hear rattling inside, the converter needs replacement. If the converter is broken inside, it will cause the P0420 to set.

 

Does the cat relate to the sputtering issue I have been having as well? I wasn't sure if they could be realted, I figured it could be possible it's screwing with the air sensors which is telling my engine to run lean? Is that possible?

I also noticed a RPM drop when I do a hard brake, say I was going a little too fast and come up to a red light, when I finally slow all the way down I get a slight RPM drop to about 500 rpms and then it goes back to idling around 800rpms.

 

Yes on the broken cat internals could cause sputtering as the exhuast is clogged-up.

Regarding the RPM drop when doing a hard brake: this could be the TPS is dirty or the transmission torque converter is not unlocking real quick. I am not very knowledageable when it comes to auto trans...but check fluid level is the first thing to do....and when was trans fluid/filter last changed?

 

You'll need to inspect the inside of the converter. If the substrate just broke apart and is rattling around, it indicates the converter just failed. If the substrate had a meltdown and is rattling around, then you need to look into what caused the overly rich condition with the engine. If you don't find and fix the problem, the new converter will do the same thing. LannyL81 is right about affecting engine performance if it's clogged, and both break up and meltdown can cause it to clog.

 

Use your hand and bump the cat...when cool of course. If it rattles...it requires replacement. I know others just replace the cat itself, but I still say the best is to replace the entire cross-over, pre-cat, and cat assembly....yes it costs more...but the pre-cat is not available itself and likely it also needs replacing, so might as well replace the entire assembly.

Just my $0.02 worth.

 

I had my mechanic pull the cat and he said it looks fine, it looks like something else was rattling when I hit the cat possibly a loose hanger or something?

My exhaust smells a little rich, and I still have the SES light on. The shop that did the fuel pump is trying to charge me to check the fuel pressure and everything so I may need to figure out how to do it myself.

I ran a can of seafoam through the truck this weekend which seemed to help with the sputtering, now it's just more of a delay before it "catches" and actually goes, basically when I hit the gas it doesn't feel like the transmission catches and goes until about 1k rpms then its fine. And when I brake I get the RPM drop most of the time still.

 

Checking fuel pressure and leakdown takes less than 15 minutes. Most auto parts stores rent fuel pressure testers for free, (you get the deposit back when you return the tester). They also sell them for ~$40. When you have one available, let us know and we can guide you through the procedure... nothin' to it, really