So, what's different than the greatest hits from this model's codes?
2 years ago, had same code, I replaced the spark plugs, wires, ignition coils and module. Under the module facing the bell housing I added copper Anti seize. Probably shouldn't have. I made a serious mistake torquing both module bolts and snapped off. Since then, I've been fastening only the lower module bolts. Yet, the codes disappeared.

Now, I'm receiving the same codes, I replaced with new parts last weekend.
The "service engine soon" light disappeared. But, when i pulled a load, codes returned.
Have 2 issues. 1) the codes reappearing with new parts installed and 2) the fasteners stuck beneath the holes.

1. What type of diagnosing will I have to do? Check resistance on all of the parts? Perhaps they're defective? Anything else? spark plug test, vacuum hose leak test? Fuel injector diagnosis, perhaps? What type of thermal paste or goop should i use underneath the module to protect it from heat?

2. Drill & Tap the Fastners? I tried drilling them. I'm having issue with the drill being too big to have a good angle with the a/c hose getting in the way. What methods can I use for this type of issue?

 

I will have to look up the 341 but 304 is cylinder 4 misfire. How many miles and what did the #4 plug look like? When was the last compression check? How much oil does it burn?

 

P0341 is a cam position sensor code. I have never had an S series car so I do not know if they have a cam sensor or if it is inferred like an L series is.

 

P0304 - Cylinder misfire detected.
P0341 Confirmed Camshaft Position Sensor "A" Circuit Range/Performance Bank 1 or Single Sensor

• 2001 Saturn SL1, 156K miles
• New spark plugs. When i removed the old spark plug. It looked clean. I can check the installed plug and report back.
• I have not performed a compression check.
• No oil burn. The tailpipe is clear of smoke.
• There is no cam sensor. It is inferred.

 

I had the P0341 code from a corroded #4 spark wire wire after a body shop left the car outside with the hood off and it rained.

 

P0341
Use stock NGK plugs for an SOHC Saturn. That's what this engine is designed to run on.

Also, the coil packs that are held in by those 4 bolts--- the bolts are what ground the coil pack to the bellhousing. It seems that if you broke off two of four, but still had one bolt holding each coil pack on, it should have worked okay ish. If you look at the holes where the bolts go through, there is a metal surface, I think it's copper, that the bolt touches and then goes through the hole and into the bell housing.

Do not put any crap of any type between the bell housing and the bottom of the icm or the bottom of the coil packs and the ICM. It's not going to seize and things are not grounded that way in this particular situation.

Take a piece of very fine grit Emory Cloth and shine up the top of the coil posts. Corrosion here can do weird things. It's not always visible.

Take out the two new bolts and put in the two old bolts you were previously using. Make sure the underside of the head of the bolt that touches the coil pack is free of scuz and corrosion so that you get a good ground.

Try each of these ONE AT A TIME and see if any of them get rid of the '0341. Try plugs first.

If you do four things at once and the problem goes away, you will never know what the actual problem was and if it happens again you'll be right back where we are, so take the time to make changes one at a time if you want to learn what's going on.

Have you tried an easy out on the broken bolts?
I would suggest using a drill like the following



Right angle drill

You'll probably need a longer drill bit if there are clearance issues. You'll need a steady hand to keep it from wandering and to keep the drill bit parallel to the hole.

If it comes down to it, there's nothing stopping you from removing the serpentine belt and removing the AC compressor and its bracket if necessary to get the lines out of the way. Obviously you would leave everything hooked up and just you relocate the compressor so it takes the lines out of where you're working.

PO304
Once you've replaced the plugs, clear the codes and see if PO304 comes back. If it does, play whack a mole with the plugs to see if moving the number four plug to a different cylinder and moving that cylinders plug to number four still gives you a cylinder 4 misfire or if the misfire moves with the plug.

I believe both of these codes take a few key cycles to turn themselves off if you do not have the ability to clear them.

Please report back with results. Remember, plugs first.

 

Cam sensor is also inferred on the L61 in Ion and an L series. It looks at KV from the coil pack to determine when #1 fire and is set until the next start. My L61 has two coils firing four cylinders like the S series. It is magic to me how it knows which side of the coil is number 1 and which is number 4. Some of this is beyond me. I worry about different stuff like whole house generation when the power is out. And managing a fleet of 100+ trucks on a daily basis.
My series of cars has coil pack failures usually on #4 cylinder in the coil pack because of failure to replace spark plugs at recommended intervals. Extended plug gap leads to high KV and overloading the coils and specifically the “wire” whether it is a wire or a path in the coil pack.
I have seen this over the last 40 years as failure of distributor caps or plug wires. GM HEI distributors had .060 plug gaps and when the gaps approached .080 to .100 gap the spark would jump to ground through the rotor and the car or truck would quit running. This was in the late 70’s.
Back in the 60s cars really didn’t pollute more than the new cars, however you had to tune the engine every 12,000 miles. Points, plugs, and condenser. If you had an import you had to adjust the valves also.
They don’t make them the way they used to! I am pleased that they don’t, the 80s were rough! We used to say don’t buy a mid 80’s anything. The transition from carburetors to electronic fuel injection was rough.
Right now we are struggling with Diesel emissions, but we will figure it out. The gas engines are doing okay now, they are still playing with “variable displacement” but they will get past that.
It is ridiculous that I can drive my 7 mpg 95 Chevy 454 shop truck in California but my 11 mpg 6 Liter Ford is a no-go. Not really sure California has a clue.

Sorry about the ramble but I have been out of town for the last few weeks.