Code P0300 & P0340, engine idling low, exhaust very puttery

[CDJuda]

Vehicle is throwing codes p0300 & P0340, engine is idling at 500RPM, stalls occasionally at red lights, exhuast is super puttery, almost like a V8 except higher pitched.
Suspecting that it was the camshaft position sensor I replaced that & to no avail.
When I opened the hood I was kinda surprised, the engine is shaking so much in the bay it looks like it's going to shake itself out.

Was wondering if anyone here could provide some insight on what this could be.

Many thanks!

 

[Blckshdw]

Mileage? Spark plug replacement history? How long's it been doing this? Need you to paint a full picture for us.

 

[HARDTRAILZ]

I would be pulling plugs and coil packs and inspecting. Esp cyl 4.

 

[Capote]

Yeah sounds similar to what occurred when one of my coil packs went bad

 

[littleblazer]

Do you have torque or similar? If so set up misfire counts on all cylinders and see if one just soars sky high. Then switch it for the next one in line and see if it follows it.

I agree. Sounds like when my coil pack went out as well.

 

[CDJuda]

Haven't replaced the spark plugs, pretty much ever, as best I can recall. 130,000 miles.
Gonna start with that and see what happens.
Will report back sometime tomorrow, I've got work and class today.
Thanks everyone!

 

[Blckshdw]

Yeah you're overdue. Hopefully that's all it ends up being.

 

[Mooseman]

The P0340 (camshaft sensor) is unrelated to the P0300 (random misfire). Did you check the wiring to the sensor?

Do replace the plugs (ACDelco 41-103 only) and clear the codes. If P0340 persists, look at the wiring.

 

[CDJuda]

Camshaft position sensor replaced and no luck, replaced all of the spark plugs as suggested, no avail.

Guess I'm going to start looking at the coil packs, any idea how much these things cost?

Gonna get the codes cleared again today and see what I get.

 

[littleblazer]

Mine was like 50 from autozone

 

[Gerbil21]

Camshaft position sensor replaced and no luck, replaced all of the spark plugs as suggested, no avail.

Guess I'm going to start looking at the coil packs, any idea how much these things cost?

Gonna get the codes cleared again today and see what I get.

Before you buy a new coil check which cylinders are misfiring with torque or car gauge pro, if it's one or two try swapping those coils to another spot and see if the misfire follows

 

[littleblazer]

Before you buy a new coil check which cylinders are misfiring with torque or car gauge pro, if it's one or two try swapping those coils to another spot and see if the misfire follows

I agree. [emoji6]

Do you have torque or similar? If so set up misfire counts on all cylinders and see if one just soars sky high. Then switch it for the next one in line and see if it follows it.

I agree. Sounds like when my coil pack went out as well.

 

[Capote]

Or just unplug and replug each coil pack. If it sounds better/runs smoother when you unplug one vs. the others, then there's your problem coil pack. That's how I diagnosed my bad one.

 

[littleblazer]

If his plastic is as heat cycled as mine was, that'll be interesting.

 

[CDJuda]

OBDII reader pointed to cylinder 1, replaced the ignition coil and it's running like new!
Thanks everyone for the help!

 

[Jeremy2994]

To future readers, coil pack 1 and 4 are the most likely to fail in some cases because of water and moister that enters from the outside and puddles on the valve cover. For me these were the coils that always failed and had to get them replaced because they had water around the spark plug.

When you get P0300 code random misfire it's always good to check coil #'s 1 and 4 first before anything.

 

[Capote]

OBDII reader pointed to cylinder 1, replaced the ignition coil and it's running like new!
Thanks everyone for the help! [emoji2]

That's the one that went bad for me lol