I just bought a 04 Commemorative Edition Z06 with less than 3000 miles on it. It has a Procharger that was professionally installed along with dynatech long tube headers, 42# injectors, and fuel boost pump. Its also has a modified intake track (replaced smashed tube looking thing over the radiator with full open pipe - modified the radiator mount to install it). The car was originally tuned with 575 hp at the rear wheels. The check engine light comes on 90% of the time - every now and a again it goes off, only to return.

I took it to shop 1 and they pulled a code for the Cam position sensor (CMP) they replaced the sensor (after they had the car a week). I became doubtfull of the skill of the techs at the shop so I took it to shop two (highly reputed for high horse power mods to the LS1, LS2, LS6 and LS7 series). I'm not even sure they replaced the sensor. Check engine light came back on.

Initially it was throwing a P0175 code for the rich side of the air fuel map. I had the car retuned (left the details to the shop experts) resulting in 513 rwhp. The tunner claims thee original tune was very "fat" and leaned a little on the top. So I lost some HP in the process but it should be a more reliable and safe tune (this is a street car and will remain as such). Check engine light went out - for about three miles.

Now its throwing the 343 code - high voltage on the cam sensor. It will be another three days before the shop can look at it (terrible service). From what I've learned, this could be caused by everything from a worn out cam (not with only 3000 miles on the car) to mis-routing of the wiring (too close to secondary ignition components - what ever that means).

How common is this? Would I be better off takiing the car to a GM dealer? This does not seem to have anything to do with the SC installation or tune. I've had the car three weeks and cant get it registered with the stinking check engine light on. Bank is starting to wonder about the getting the lien recorded....any advice. I'm in the Houston area and need some advice from a c5 owner....(cant trust the shops).

Thanks in advance,

John

 

Hi---If the car seems to be running fine it is probably a false code--Happens quite often with moded engines---If you are in a pinch to have it smogged and you believe it will pass regardless of the code---which I think it will---Just have someone with a tuner turn the DTC MIL Enabler OFF for P0343 and also turn the DTC Processing Enabler to "NOT REPORTED " for P0343-- the check engine light will go off and so will the code---You will have to drive it thru 2 cold/hot engine cycles to re-set the readiness tests so don't take it immediately to the smog shop --only after a few days and a couple cold/hot engine cycles.

Anyone with a full blown tuner can do this--you can even do a mail order tune but ask them not to touch your tune and only to do what I mentioned above--The dealer can't do it--Someone with EFILIVE or HP Tuners or LS1 Edit can----For only 2 things the charge should be not much--$50-$100.
Also the Cam position sensor codes usually can be corrected by doing a "Crank Position Sensor Relearn " procedure-Again it takes a full blown tuner and must be preformed on the car though----And also this happens with mods such as heads-cam--forced induction- etc--major mods-----If you would like to discuss Im a tuner and would be glad to talk about it--Send me a private message----Tom

 

Loose cam bolts, it happens alot when FI is added. Ask me how I know.
It could be the sensor or damaged wiring, but most of the time not.

 

Funny co-incidence there.

My car is at a Houston GM dealer with a P0343 code as well. (the engine died while driving home about 6 miles after the code was posted)

But it would seem the code cam after some mechanical failure. The dealer has the valve cover off, and they say when they went to do a compression test the valve train isn't moving.

They suspect broken cam chain or broken cam.

I guess the moral of the story is the P0343 code could be a "false' code, or a the indicator of big problems about to occer.

BTW, when the dealer was "diagnosing" the issue, they claim the car backfired so badly it blew th valve cover gasket off the motor.. is this even possible?

 

Now I'm scared. I should have noted though that the car only has 3500 miles on it. It was supercharged with a procharger at around 1600 miles. I've also noticed NO issues with the way it runs. It idles smooth and has no strange noises or hesitation. But now I have to ask - how on earth can a bolt on SC kit result in loose cam bolts?????

J

 

As in my last reply ---how can FI loosen cam bolts??

J

 

Because they are not lock tighted by the manufacturer, this is not "common", but common enough. Do yourself a favor and do not drive it anymore, or at least just limp it to a shop close by. Have the timing cover removed, bolts locktighted, and off you go.
There are other possibilities, but this is the only thing I have ever seen set the 343 code.

 

I got the same code last year, and yes, cam bolts were loose. See my pics here in this thread:

http://forums.corvetteforum.com/show...ighlight=P0343

Pekka

 

Anyone ever have this code without the cam bolt problem?

 

I had this code from when I installed the new motor because the 2 outside wires on the LS2 to LS1 converter cable had the polarity reversed. My car was hard to start and would make popping and farting sounds in the intake and the exhaust would grown. Once I swapped the 2 outside wires around it went away and the car starts better now without the previous issues.

I would be suspect in your case because you have a stock motor with no lock tight on the bolts and i have also heard of the bolts backing out after putting a blower on them.

My LS2 motor was built by A&A so I had called Andy to ask him about my issue and he told me to reverse the wires as he had seen this issue before with the wiring harness I was using and it worked.

Hope this helps!

 

It ended up being loose cam bolts.

 

The funny or not so funny thing is that when I bought new cam bolts from the dealer they have locktite on them.

Hopefully no damage was done. On mine the guide pin was pulled out. I found it in the oil pan.

 

With the added torque from the crank applied directly to the camshaft via the timing chain.

 

I had that code. 2 of the 3 cam bolts only had few threads left until they would have fallen out.

While you are in the engine that far you might as well add a blower cam if you don't already have one

 

http://www.z06vette.com/forums/f55/p0343-danger-107381/

I am sure most of the replies are from the same set of guys on here. But to add to the list of folks with the screws backing out, check out the above post.