Ignition coil

[Pikemaster101]

I think I have a bad ignition coil on my 01 Silverado hooked it up to the computer and said random cylinder misfire what is the best way to figure out what one it is that is no longer working?

[PierBridge]

With the scanner go into misfire history and find out which cylinder is misfiring the most.

It could be many other things besides the Coil!

[jwhjr]

Yep, random misfire is the red herring to many issues

[Scott K]

What engine is in your truck? I have heard of alot of cat converters being plugged. Have you noticed a lack of power, or a missfire? Or just the check engine light being on? I have seen some 6.0 that need a ckp relearn also if it has the 6.0

[Jeremy airjer W]

P0300 random cylinder missfire suggests that more than one cylinder is acting up and in no particular order. For example 1 may misfire then 3 a couple of times then 1 again then number five. It would be a good idea to look at the misfire data to see if one or more cylinders have higher counts than the rest and concentrate on those. The solution could be anything from a simple tun-up, wires, coils, injectors, etc.

How many miles do you have on it, Is the check engine light flashing (I'm guessing not), and do you feel the misfire (again I'm guessing not)?

[Pikemaster101]

I have a 5.3 with 150,00 miles on it. Yes the light does flash but it only does this in third gear and when i have it in the tow/haul mode. when this light flashes at me i do notice a lack in power and also it acts like it does not want to shift or somthing.

Yes i was also told about the cat converters how hard are these to clean your self??

Any sugestions

Thanks

[Jeremy airjer W]

If the misfires are all even or all odd cylinders I would be suspicious of a catalytic converter. I have run into miss-fires like this and new cats have been the fix. If they are plugged they will get replaced. The last ones I did where around a grand parts and labor.

[Pikemaster101]

Any other suggestions on what to do or try with this problem i do not want to go and put thousands of dollars into this and find out it was something simple.

So is there any way to clean the cat converters?

Thanks again

[Scott K]

Quote:

With the scanner go into misfire history and find out which cylinder is misfiring the most.

This would be wise at this point! See if the ones that are missing are all on the same side of the engine, see when it is happening, cold, hot, driving down the road, ect..

One way to see if it is a cat converter is to drop the exhaust down from the manifolds and go drive it, if it doesnt do it then, you have a plugged cat! Nope, no way to clean them! Sorry!

[Jeremy airjer W]

Usually one of three things happens to a cat. It either loses it catalyst efficiency, it breaks apart, or it plugs up. In all three cases replacement is the fix. I am not aware of any "cleaning" process that is available at this time.

If there is not an easily identifiable problem, like the plugs are worn out or the wires are leaking, or there is weak spark out of a coil, than you should seek professional advice. We don't want you to spend that kind of money if you don't have to as well!

[Macgyver55]

We don't want you to spend that kind of money if you don't have to as well!

If it turns out to be the cat converter here is another suggestion.... There are universal units out there that work pretty well (at least on the GMs they do) and are far less expensive than a full one piece exhaust assembly. (Like 900 bucks cheaper) I install maybe 6 or 8 a year on our units and have had good luck. In most cases, because of the nature of the one piece exhaust assemblies, you have to cut out the old one and weld in the new one. Its still way cheaper to do than replace the whole thing, and more practical on a high mileage unit.

[PierBridge]

Thanks Macgyver!

Where do you guys get the aftermarket Cats?

[Macgyver55]

The ones we use are made by Walker, a major supplier of exhaust parts. I dont do much parts buying, we have a computerized parts system. I just pull one off the shelf and magically there is another one there the next time I need it. I can find out, but the boss isn't back until Tuesday. It could be NAPA or Red Rooster since we buy much of our generic parts from them. Most everthing else that is vehicle specific we get from the dealers.

A quick look at the Walker web site shows they have a dealer locator so you can find the nearest one to you.

[PierBridge]

Thanks!