Hi all,
I start my 99 C5 coupe and she idles nicely, five minutes later she misses and wants to stall. It has caused me to not be able to pass e-check because my converters won't ready up. Here is what I did before the problem started. Changed plugs and wires, cleaned MAF and throttle body with CRC kit. Also here is my confession, I cut corners on the wires and bought E-Bay $29.99 red ones (can't remember name). Could it be the cheap azz wires?

 

My guess is that when it goes in to closed-loop after warm up that there is something wrong with the computer.

 

I would check the thermostat and see if its reaching 160 degrees or more, if not it stays in open loop.and check for stored codes.hope this helps, good luck

 

Well I am praying you're wrong 73shark. I am just getting her out of storage and will check codes when settled. TY for your response.

 

The thermostat never crossed my mind. I am just getting her out of storage (she went in with this problem) and will check on this first thing. TY for your response.

 

Problem solved, I couldn't get the plug wires out of my mind because I was so mad at myself for being a cheapskate and buying BS wires. JDMspeed Red wires to be exact and I highly recommend to NEVER buy these. I learned my lesson. Here is a picture of what caused this mess. The connector at the coil broke off. Bought Summit Racing Red 8mm SUM-867828R wires and she runs like the day she was born. Thanks to all who replied and I hope this may help someone who may have bought these wires.....perheiro