I recently installed a Vortech V-3, T-trim supercharger kit from A&A (w/ 60 lb injectors) + longtube headers and a ported throttle body into a 2004 Z06. Since starting her up, I have been getting the P0300 code. I have replaced all sparkplugs a second time as well as changing the sparkplug wires again. Also tested each coil with a timing/strobe light and all seem to be good. When I hook up a scanner, it sporadically states P0301 (and always shows P0300, just like the DIC) but I’ve check & rechecked cylinder #1 and it seems fine. When I listen to the engine while the car is running, it seems the misfiring occurs on Bank 2 (can hear the actually misses); this was also evident with the strobe light when I was testing coils as there was a slight miss on cylinders #4 and #6. Also, I noticed a strong gas smell and when actually smelling each exhaust tip, I can smell it from only the passenger side exhaust tip, though I do have an X-pipe which is probably crossing the gases. Also, the freeze frame data from my scanner is showing the following for P0301:
STFT B1 0
LFTT B1 25%
STFT B2 0
LTFT B2 4.6-6.2%
Why the large variance between Bank 1 and Bank 2? Oh, I have also replaced the O2 sensor in Bank 2 (passenger side) but it hasn’t changed a thing.

While the car is running, the scanner displays the following “live data”:
O2S B1 S1 (V) 0.445
STFT B1 S1 (%) 0
O2S B1 S2 (V) 0.445
STFT B1 S2 (%) N/A (rear O2s removed)

O2S B2 S1 (V) 0.21
STFT B2 S1 (%) 0
O2S B2 S2 (V) 0.445
STFT B2 S2 (%) N/A (rear O2s removed)
Again, why the discrepancy between O2 sensor#1 in B1 and B2???

Can anyone point me in the right direction? I feel like banging my head against the wall with all the problems I have been having with this install. Thanks to everyone!

P.S. – Also have HPTuners so I can post data if needed.

 

So the supercharger kit was the only thing you installed...nothing else? Also, did you have the PCM programmed with a base tune for the mods?

 

Hi, Lucky131969 -

Thanks for your reply. I installed:
* A&A's V-3, T-Trim kit w/ 60 lb. injectors,
* Katech's ported LS-6 throttle (though have been going back & forth with stock LS-6 non-ported TB),
* Longtube headers with NO cats and no rear O2s,
* Bunch of other stuff that shouldn't affect tune (Katech valve covers & coil relocation kit, Black Magic fuel rails, silicone hoses, T-1 suspension).

Yes, loaded a basetune to correctly flow the 60 lb injectors and to account for no rear O2 sensors. Also had the basetune tweaked for my other mods but it still is having the same misfire issues all the way through this.

 

PM Sent.