I have notice that my LT1 has lost some of the low end TQ, and when I floor it isn't down shifting so agresively like always..

I have notice some fuel smell from the exhaust and is has a very slight rought idle, that only causes the exhaust system to vibrate a little.

also I have notice that the oil gauge is a bit erratic, and the head lights of the car sometime get dim and quickly go back to normal..

can that be the opti starting to fail?

or a bad spark plug wire?

 

miles on car? A bad opti wont mess with your lights. Now it sounds like you may have a bad alternator, or it just may be your fans coming on and creating a sudden load on the alternator which is normal. How much of a dim? Liek a blackout or alittle less brightness for a split second? Rough idle could be many things, i would do a little tune up first, maybe do plugs, wires, fuel filter, clean iac and tb, clean the MAF, and check/replace o2s.

Aftermarket exhaust? Could just be a loose hanger or clamp. If your stock (from the factory) exhaust is rattling, something is wrong with the exhaust, not the motor, unless you have some HUGE vibration from the motor.

 

No, an ignition problem will be a severe stumbe or miss under accel/full throttle, & if bad enuff a dead miss at idle.
Maybe you have tune-up issues or along that order, you should check plugs & PCM data etc.
The oil sender may be going , common, maybe check the pressure manually with a gauge for piece of mind?
The funky lights could be a sign of an impending alternator problem, all of which should be checked out.

 

I replaced the opti, ac delco wires and the plugs 41-906... my LT1 only runs fine with them

And is back to normal, the and the vibration wasn't the exhaust, it was a metal part from down the car that was loose!!


Thanks guys

 

So you replaced these before or after the post you made?