zuperzport01

I'm new to this site so I hope I am doing this right. I need serious help... I have an automatic 2002 z28 43k miles, it has an LS6 intake, shifting kit, magnaflow exhaust. I have had it for about a year. It was running great until I took it to get both of the catalytic converters changed today. they cut out the bad ones and welded on my new ones. My old ones were pretty hollow. New ones had silicon inside, looked as though it would reduce air flow idk. Left the garage and it ran fine, just a bit quieter I thought it to be normal. I had just got home and it acted as though it wasnt getting power when I pushed the gas. I pulled into my parking spot and it idled low and died. I checked the codes and it ran a p0354 which was Ignition Coil D Primary/Secondary Circuit Malfunction, I located the Coil pack(Which I changed last summer already) and changed Coil pack D over cylinder #4. Started it up after clearing codes ran ok then started acting up just not as bad as it did. still idles rough and takes about 3 or 4 min to die. just acting like its not getting air or fuel. Computer now reads p0300 cylinder misfire, p0506 Idle Air Control (IAC) System RPM Lower Than Expected and yet again p0354 Ignition Coil D Primary/Secondary Circuit Malfunction. I start it and it just idles and dies. I changed spark plugs and wires. HELP! could it have anything to do with the catalytic converters? o2 sensors? or MAP sensor? Fuel pump? if so how come these codes are not showing up? My computer is brand new. Please help

armintheman

iTrader: (31)

bump for the new guy. im experiencing something similar but i removed the cats and had the car tuned. since then i realiezed i had a small vacuum leak so i think my tuner set the computer tune to work with the leak and now that the leaks is gone the idle is too low...idk this problem started today so im still trying to figure out what it could be

346ci

First thing I would do is check fuel pressure, it's a quick check if you can get your hands on a fuel gauge

FiredUpZ28

Bummer I bet you missed GMs extended catalytic converter coverage by just a hair. Did mine last year under 10 yr/120k mile GM special policy.

The IAC code could be because of the ignition misfire, but I'd get a can of cleaner and clean it out anyways. May help a little. Has your car had any aftermarket tuning at all? Unless its been to long, would hurt to have the shop that did work on it last look it over.