What would cause?

[JEFNLSA]

Jeff,

You can turn the ignition switch to ON (immediately before engine cranking) and read battery voltage from the digital gages. This is how many volts your battery has. You can then start the engine and read the same voltage; this is how many volts your alternator is producing for your battery. Two readings, as far as I understand, are two altogether different things. If you have lower than 12V at ON position your battery is dead meat.

I had my SES light on and off like yours when I first got the car. It ended up being the O2 sensors. Never saw that SES after replacing all 3 x O2 sensors

Good to know....thx Selim Was the car running any differently or was it just the intermittent light that let ya know the 02's were bad?

 

[JEFNLSA]

I'm not Gordon Killebrew the Evil Genius that invented this stuff but think it goes into a history folder and doesn't stay on all the time. Just a loose connection or clogged EGR could come and go. The answer lies within the little black connector pointing at your privates.

Yeah, I'm gonna get it scanned ASAP although the SES light is not on...for the moment. Thx

 

[SSTibet]

Jeff, I had the car scanned. It is an easy job that the mechanics do in a matter of minutes. Your SES warning does not have to be on for the scan. Error code(s) is stored in the PCM memory. The car was running fine with bad O2 sensors. I had a rough idle also but it was due to poor quality fuel.

With the higher end sophisticated scanners the mechanics can also give a thourough check of the engine such as compression testing of individual cylinders. It is like a quick health check up, only in a repair shop... Get it done & you will not be sorry.

 

[vette-dude]

I would suspect it is throwing a code for the EGR valve or system problem. It may be the O2 sensors but since it goes on and off I would suspect the EGR valve. I am just guessing as I have an L98 and it does the same thing. Each time I read the code it is an EGR system problem. Very intermittent problem and cars runs fine always. Someday I will have to replace the EGR valve but will do that when I upgrade the fuel regulator. Yours may be different and easily accessible, don't know for sure as never worked on your LT1 motor. To replace mine involves some tear down of the runners and plenum.

Randy

 

[SSTibet]

Replacing EGR on an LT-1 is a 10 minue job at the most. I had mine serviced once and it was a quickie. But that is besides the point. You can either keep on guessing what maybe going or wrong and find it the hard way, or can get the car scanned and find it almost right away.

Get the car scanned.

Cheeeeeers,

Selim

 

[JEFNLSA]

Get the car scanned.

Will do...
Thx to all for the input.
Jeff