PHANTA-Z

Car is a 2004 GTO, forged 347, heads/cam, T-trim blower. Codes are PO 342 and PO 343. Also getting a TPS code as well. Any help on this is appreciated, we've tried everything we know to try at this point. All grounds and wiring have been checked by no less than 4 people, we've pulled the cam and checked it for endplay and walking, we've re-insulated all the wiring that comes near the coil packs (secondary intereferance), replaced the entire PCM ($360 for nothing there), reflashed it at least 3 times, etc. We are at a loss here. Anybody with any experiance with these issues please chime in. TIA.

strokedls1

iTrader: (1)

Have you replaced the cam sensor. I had a bad one on my car and it didn't even throw a code. Just ran like crap. If you are going over 100% because of grinding the tb bump stop that could throw a code. I would try swapping it with a friend if you know someone to borrow one from.

PHANTA-Z

Yeah we replaced the sensor first thing. This has got a lot of really smart people stumped, and its holding up a $31,000 build project. Any advice is welcome. Thanks guys.

assassinz28

iTrader: (10)

my car is running like crap too and I don't know what it is is doing the same thing misfires and any info you find out please let me know also

DrkPhx

iTrader: (15)

You should get a copy of the service manual. It has a detailed diagnostic to follow.
Anyway it's odd you're getting the those two codes because code PO342 indicates low voltage and PO343 indicates high voltage. Per the manual conditions for setting DTC PO342 "The PCM detects the cam signal is stuck low when it should be high for 5.0 seconds." Conditions for PO343 would be opposite of this.

Possible mechanical mechanical condition that may cause this code:
* Poor connection/terminal connection at the sensor.
* Camshaft reluctor wheel damage.
* The sensor is coming in contact with the reluctor wheel (check for vertical lines on sensor).

Once again this is a small part of the complete diagnostic procedure which concentrates on checking the correct voltage to the sensor and looking for shorts or opens.

CATDIESEL

This is just a thought but is the cam advanced or retarded? If it is could the ecm see the crank tdc and the cam tdc too far apart and think the cam isnt were it should be? Or is it aftermarket crank with the pickup wheel possibly in the wrong spot? I may be totaly out in left feild but thought I would try to help

strokedls1

iTrader: (1)

The only other thing you could try is have john at speartech make you a new plug with wires, and swap it out of the computer harness. Doesn't seem likely though. Never thought about the crank reluctor wheel being off, but I would think if that was the case it would give a crank position sensor code. Sounds like you are working with smart people. Maybe you need to call the ghostbusters for those gremlins. lol