BabyGT

Ease off on additives, and running higher octane is not good either, higher octane will not burn better or make the car run better. It's designed and tuned from the factory to run on standard grade fuel. The sputtering you say you hear, what's your exhaust setup? I'd call that an exhaust leak.

Villiska

I just figured the 93 would flush my fuel system more with the detergents. I won't be using it again. As for my exhaust setup, I'm not sure honestly. A custom one was put on before I bought the car, I think it's a true X pipe which apparently isn't stock on the V6's.

As for the exhaust leak, why would the sputtering just now be happening when the RPM's have began fluctuating and the idle is poor? I know I've been hearing a loud rattle under my car since I bought it that has gotten somewhat worse at certain times. Especially when the car is warm after a long drive. If the car is cold you rarely hear it, but once she warms up the rattle happens every time I press the gas.

Maybe the exhaust is coming undone and I should get it on a lift and look at it?

Daehawk

That rattle could be valves.

Villiska

It's a much different kind of rattle from what I've heard on Youtube videos just now of valve rattle. It genuinely sounds like there's something loose under the vehicle.

The last time I changed my oil, I tried to reproduce the issue while it was up on jack stands and I looked under the car to see if there was anything noticeable but I didn't find anything.

PNYXPRESS

IAC=Idle Air Control

K&N filters are good but I know of a few instances were the oil gummed up the MAF (mass air flow) sensor, clean both and don't re-oil the filter

This could be causing a bigger issue than you originally had. Seafoam is petroleum based and doesn't burn as easy as gas. This is why the instructions say only 1/3 can in the fuel tank

Villiska

Ah, I mean the 2 separate cans were at 2 separate times. Their website online says 1oz for each gallon of gas you have and my car runs 15.9 if I'm not mistaken, and their typical bottle is 18oz. They say 2oz per 1 gallon is completely safe to use, so I didn't mind the extra couple of oz.

Either way, I'm not going to be using any more cleaners anymore. I would like to clean my vacuum lines out though, if that would help anything. Would I just want to seafoam those or is there a better method?

Villiska

Just ran the codes and got these:

P0340 - Camshaft Sensor A Bank 1 Circuit Malfunction

P0411 - Air injection system incorrect flow (I've had this code since I bought the car. It has to do with emissions and it's had this code long before I ever had any of these relevant problems. Cleaned the MAF in the past and it didn't fix it. We concluded that it was because of the BBK headers that's on the car but I don't know.

P1309 - DTC Definition Not Found. See service manual.

Alright, so I saw that a sensor was malfunctioned so the first thing I thought of was that maybe I hit something while I was installing the thermostat since it was such a pain for my hands to get in there. Sure enough, there was a sensor above it that was undone a bit. I replugged it in and pushed down to make sure it was in and restarted the car. The sputtering is gone, but the RPM fluctuation is still there. I'm unable to determine if this is the same RPM fluctuation I had yesterday, or if it's the one I mentioned in a previous thread that only happens when the car is warm, because it was warm when I ran the codes.

The last code is related to the camshaft sensor which I think came from the sensor being unplugged a bit. I'll need to reset the battery and run the codes again to see if it was fixed. I could be completely wrong about all of this though so I guess it's just a matter of time.

Villiska

Looking into what BabyGT recommended about the IAC, I've read about it and it sounds exactly like my issue. Good start, rough idle, give it some gas and it smooths out. That's exactly what happens. I'm going to give the IAC a good cleaning and possibly replace it if needed, and while I'm at it I'll check the MAF and see if it's dirty.

Would it be a good idea to run seafoam through the vacuum lines or should I just leave that be?

PNYXPRESS

PUT DOWN THE SEAFOAM

Haha

Villiska

Hahaha, okay okay!