Captainkelp

About a week ago fired up my 2006a6 and it sputtered a while in neutral. Put it in drive and as I was driving down the road, it almost died. I then gave it a bit of gas and the problem seemed to remedy itself. Yesterday, as I was driving on the highway at normal speeds, it again started to die and I had a complete loss of power. I gave it some gas hoping it would not die, as I was on the freeway in the #1 lane, and it bogged and then backfired, shooting a white plume of smoke out the back. After that, i had power but it sounds totally different. I have BB Bullets and although they are loud, I know what my car should sound like. It sounds muffled and runs rough, occasionally still sputtering.

I hooked up a code reader and P0300 (misfire) came up. I can tell that I have a loss of power and like I said, it sounds bad. The car only has 23000 (but no warranty, over three years) and all I have ever done is Bullets and a predator tune. I have since put the stock tune back in and tried some octane boost with the fuel injector cleaner in it.

Any ideas of where to begin would be very helpful, otherwise I guess it is going to the stealer on Tuesday.

Thanks all,

Captainkelp

Captainkelp

Anyone? I guess I will pull all the plugs and if they look fine, maybe change all the coils.

Bill Curlee

Engine misfires for some reason.

First,look at the plug wires and make sure that there in good condition. Not torn, properly secured to the coil and plug. If all thats good, could be a bad connection on a coil or injector plug/connector.

Do you have a vacuum leak that is causing the engine to miss?

Clear the DTC and see if it runs properly

BC

Captainkelp

Plugs look good and all connections are secure. Not sure how to tell if I have a vaccum leak. Starting to think that it may be a crankshaft position sensor from internet articles that I have been reading. I cleared the code and even disconnected the battery, but it is still running poorly.

martysauto

since you already cleared the code you won't be able to see the "freeze frame". look at the misfire monitor, it will tell you what cylinder/s are missing. test compression, then you can try swapping plugs, then wires, then coils, then the injectors with ones from known good cylinders. you will find the problem easily without wasting money "throwing parts at it".

Captainkelp

The dealer said that I had a burnt out right cat, and that only 3.5 PSI was getting through and thats why it was causing the random misfire. Can anyone tell me if that sounds legit? They said it was covered under the emissions warranty even though my normal warranty was expired.

Thanks

Bill Curlee

If the dealer wants to replace the CATS under the 8/80,,,by ALL means,,let them accomplish the repair. YES,,that can cause the car to run like CRAP! Your on the POSITIVE side of the equasion!

BILL

mjorgensen

A plugged cat can cause real engine damage very quickly so make sure they check out the rest of the system to find the root cause and see if anything else was hurt. Burnt valves or piston damage?

Sparo2

A bad cat can definately cause your car to sputter. If it's plugged then the cat won't allow one bank to exhale, which will also build up pressure on that bank.

I say let them swap it out.

Captainkelp

Thanks all, the dealer did the swap and it is running great, except for the terrible shifting (I hate the stock shift parameters), but I need to put my tune back in. I asked about internal damage and they stated everyone looked ok, so hopefully no extra damage was done during the time the cat was burnt.

Thanks again,

BTW almost traded it in that day on a 09 Z06 that was on the showroom floor. 77,000 and 0% APR for 72

AORoads

I agree with the above. A plugged cat doesn't randomly happen at 23K miles. Since the only changes to the car were the exhaust which is catback and a tune, have you determined which, or what else is the cause?

Vito.A

Glad to hear you got it fixed.
If you do decide to go with the 09 Z06, shoot for $10-15k off MSRP and then 0%.

HANNY

a missfire from a plug,coil,wire isnt gonna completely almost kill your car, a cat would if its a car with single exhaust. Dont think so on your vette. The fix you got might be just a symptom of a bigger issue. Sounds more like a fuel pressure issue to me from your symptoms. The relay or pump possibly but hey if it takes care of it great

Captainkelp

Yeah, it could be something worse and that is why I may trade it in since I no longer have a warranty, but for now it runs great. Are they really doing 10-15k off MSRP for the Z06? If that is the case, a 09 Z06 may be in the very near future

Bill Curlee

The C5 is a FANTASTIC car!!!!!!! Ive had a 98 and 02 ZO6. The 98 was great! I absoluty LOVE my ZO6. Once you get her running,,,you will really enjoy the C5
. DO NOT let the damn STEALERSHIP, rip you OFF with this trade in thing.
Run FOREST



Run as far and as fast as you can.

Take your FIXED C5 and enjoy it. If you find that you "really" need to trade it, trade it on your terms. Make a BUCK,and STOP the FU&@.


Get away from this Stealership and then,,,,,,,,,,,,,,,,,,,,make your C5/ C6 decision. I have BOTH. A C5 Z06 and 06 C6 Coupe. I 100% perfer the C5 ZO6.

BILL CURLEE

Streetk14

I think the OP already has a C6, but is looking at maybe upgrading to a newer Z.

Andy