riotten22

Hey guys, i am a complete newbie. Picked up my first corvette. It is a 1998 with z06 heads, intake, and comp cam (not sure the cam model / part #)and a Corsa Titanium exhaust with headers (with no O2 sensors installed)

Question: When the car idles it will briefly idle at 1k rpm but then it will drop down to 500rpm or a little lower (like almost stalling) and spike back up and continue to do this. Previous owner said the spark plugs are 2 stages colder for a nitorus system that was installed. Is this all from the cam or Colder plugs or possibly the 02 sensors not being installed or maybe its something else? Car runs fine its just kind of annoying.

kinglt-1

iTrader: (26)

Has it been tuned?

riotten22

Supposedly it was tuned and dynoed at 450HP

kinglt-1

iTrader: (26)

No dtc's or ses light? I would pull a couple spark plugs and see what they look like... Maybe time for a fresh set.

trx250r

I had what sounds like a similar problem with my camaro and a mail order tune cleared it up. If the plugs look all right i would look into that.

riotten22

Should this setup have O2 sensors installed? Will it still throw 02 codes even if I put the sensors in since it doesnt have a CAT?

riotten22

Any recommendations on what plug i should use on this setup ? Should i be using the stock plugs that are recommended for the LS1 or do i need something different because of the head/intake/cam upgrades?

R6cowboy

iTrader: (3)

First things first, put new plugs and wires in no matter what. Suggestion, NGK TR-55 and MSD wires. Just so you're 100% sure there's good plugs and wires in it. See if that helps. You can pick up MSD wires (long lasting) and NGK plugs in a combo from numerous places for only around $80.

If you have long tube headers and an off-road X or H pipe (no cats) the front two O2 sensors should be plugged into the headers and the rear O2 sensors won't be used. The rear O2 sensors codes should already be deleted from tuning.

My advice, if it doesn't run right after adding new plugs and wires, maybe look into getting it tuned at a reputable performance shop due to having heads, cam, intake, exhaust mods. You want to be certian it's tuned correctly. Tuning has everything to do with these engines.

NC98Z

iTrader: (1)

Invest $5.00 in a can of CRC MAF cleaner and see it that helps.

Head Hunter

iTrader: (14)

Could be plugs, could be a vacuum leak, could be IAC, could be MAF needs cleaning, could be tune... I'd find a mechanic familiar with LS1's and go from there. Did it not do this before you purchased it?

Johnnystock

iTrader: (6)

I had a vaccum leak that was causing this..At the time, my car was only 'tuned' by my Hypertech programmer BTW. Now witht he full tune, its gone and way better. Will still idle around 1200 rpm when cold and goes down to 1000 after.

TR55 for the win; you dont need colder plug N/A. Do the wires too while at it. I have MSD and they last longer than my GM LS6 wires..