Aurora - Cylinder misfire / failed emission

[atlanta1980]

Sorry if this is a repost, but i'm new here. Mod, please move, as necessary.

I have a 2002 Aurora with about 140k on it and it just failed emissions. My dad was the king of getting stuff fixed, but he passed away a few months ago, and i guess i didnt learn as much from him as i really shouldve.

I was wondering if yall could give me a little guidance. I looked up some of this stuff online, but they referenced things i wasnt familiar with; I was hoping i could get a pretty clean step by step for someone that doesnt know a ton about cars. Anyone seen this stuff before? Is it indicative of a major repair that maybe isnt worth making?

Oldsmobile
Aurora
2002
6 Cyl, 3.5 L
Auto

heres the printout from the emissions:

RPM = 1261
KOEO = Pass
Readiness = pass
MIL CMD = Fail
Codes Read = 02
DLC = Pass

DTC1 = P0128 - Manufacturer specific code
DTC2 = P0300 - Random/Multiple Cylinder Misfire Detected

 

[Cutlass350]

I'm sorry to hear that your dad passed away.

Summary:
You are looking at ~$250 to ~$500 to get the thermostat assembly replaced.
That will likely take care of those two codes.
But, of course, there could be other problems. My guess is that other problems are "unlikely".


More info:
The thermostat and housing are ~$50. You're looking at ~~1.5 to 4 hours of labor. Add in cost for some anti-freeze. Figure low-end shop, verses full service dealer, and you get the rough price-range that I specified above.


The 3.5L LX5 (what you have) has a few longevity issues.
A minor one is the water-cross-over gaskets. Figure about the same price range to get that fixed. After that, they are good for another ~100K, 10 years.

The major one is the poor cylinder head design, that causes the head gasket to go. That can cost between $1.5K to $4K to get fixed. If that was done already to the engine, the gasket(s) should be good for another ~10 years/100K miles. You'll know there's a head gasket problem when the engine starts running warm. The engine/head-gaskets may last over 200K miles. Many factors involved.

Imho, those are two of the most common problems with 10+ year old LX5 engines.

And of course, any car will need maintenance.

Good Luck!