My car is missing and I don't know why.

Well, I guess I'll state the problem and then give more detail. My car is missing, but it's inconsistent. It never does it immediately after start up. So if it's missing I can cut the engine off, and cut it back on and it runs fine for about 5-10 minutes. I've had this problem once before and I just replaced the fuel filter and put gas treatment in it. That seemed to fix it. It seems to do it worse during heavy rain and such. I don't know if it's just coincidence, and the problem started just after I drove through a huge rain storm that popped up out of nowhere. My car is a 2000 model camaro z28 with an LS1 in it. It has long tube headers and magnaflo exhaust system. Also when it starts to miss the SES light flashes. My SES light is usually always on for some reason. When I checked it with the reader it said bad O2 sensor so I changed it, and it still says the same thing, but drives fine. I haven't done anything to fix the missing problem yet. Just kind of wondering where the best place to start would be.

Thank you for your time, and I appreciate any feedback.

The flashing SES is indicating the misfire... How many miles are on it, and how long since plugs and wires?

Also.... What O2 code did it throw???

103000 miles are on it. And I don't remember the exact code. I know it was the O2 sensor on the passenger side that was replaced, but it was driving fine even with the bad O2 sensor, and replacing it didn't fix it, so I didn't worry about it.
I haven't changed the plugs in quite a long time. But the odd thing to me, is that it will start up, idle fine and run for a while and then it starts to misfire. And it's totally random. I put gas treatment in it, because I was thinking maybe it was just bad gas, but I don't know. I always run premium 93.

Clean the MAF and TB
Also change your plugs and wires.

Well, The code would help... The o2's dont become active per say until the loop closes (the car warms up) but that doesn't totally explain the turning it off, and it being fine again for a few minutes... Is this a sure bet? or only a sometimes fix?

It always fixes it, it's just random for how long it stays that way. It could be 5 minutes, or it could be 20.

My Local GM dealer will Tech II diag. for $55.00... I would say see about yours before you throw money at it.... Intermittent problems can cost alot of time and money to track down.... Try the easy stuff first (cleaning and maintenance items) If the routine doesn't fix it, Tech II will be your best (cheapest) bet.....

Your car has four (4) O2 sensors -- two (2) pre-cat and two (2) post cat, Bank 1 is on the left and Bank 2 is on the right. The pre-cat sensors control fueling as they provide feedback to the PCM. The post-cat sensors simply tell the PCM is if the cats are working properly and have no affect on fueling.

As stated, the pre-cat sensors do not do anything until the PCM switches from open to closed loop at a set coolant temp. Also, the sensors are electrically heated as they need to be at a certain temp to operate properly. A lot of times, a bad sensor is really just a burned out heating element, although the sensor's performance does degrade over time. Generally, they should be replaced at 75,000 miles.

It really sounds like you should replace the plugs and wires on your car. This is simply routine maintenance and may resolve your misfire issue. It is best to use a dab of dielectric grease on the boots before installation. Also, you should hear and feel the plug wire "click" once on the plugs and twice on the coils.

If the O2 sender code remains, swap the senders right to left and see if the code follows it. If so, you may have a defective sender. If not, you probably have a wiring issue that could be causing the problem. Finally, I would check your fuel pressure at the rail, clean your MAF and throttle body as suggested, and inspect your vacuum lines and intake ductwork for any leaks.

What mods have been done on your car?

check over your plug wires and make sure one didn't dry out and crack from either the heat off the headers or actually touching the headers.

As was just discussed in another thread -- wait until after dark and then start the engine with the hood up. If you have plug wires arcing, you should easily see the spark dancing around the areas that are bad.

But if its plugs/wires... why the Key cycle fix????

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Originally Posted by FORD RECOVERY EXPERT

But if its plugs/wires... why the Key cycle fix????

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With a random misfire, it could just be a coincidence -- hard to tell.

Yea, But its hard to believe coincidence seeing as how the OP stated it fixes it EVERY time..... :thinkin:

Do you think it might be more of a fuel pressure issue then with a lean misfire? Shut the car down and the pump runs good for a bit on re-start before warming up and the pressure drops again?

Very possible... We need the code info.... Most peeps (and vato zone clerks) pull codes, and they see Lean o2 B1S2 ... and they automatically say: Hmmmm, Bad o2 sensor.... the Idiots dont understand that the o2 is the sensor that is reading the lean condition therefore its doing its job.....

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Originally Posted by FORD RECOVERY EXPERT

But if its plugs/wires... why the Key cycle fix????

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if it's a lean condition why would it be worse during a rain? :D I think we're missing some pretty key information here. Normally a misfire that gets worse with moisture is ignition related.....not always but a lot of times. The key cycle piece of the puzzle doesn't fit it being ignition so I'm guessing we're missing some info.

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Originally Posted by 0rion

if it's a lean condition why would it be worse during a rain? :D

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I was just stating hypothetical.... Thats why I said we need the code(s).

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Originally Posted by 0rion

I think we're missing some pretty key information here.

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^^THIS:right:

quite possible your dealing with two separate issues here the first being random intermittent missfire most likely caused by coil pack or faulty wires and plugs second the o2 sensor code could easily be a faulty catalytic converter esp if the code is for a rear o2 find out what code is stored as many others have said and we can help you more