My 98 Z28 shot out a P1416 SES light. After using our SEARCH function here I found the most common issue is the passenger side Air pump check valve off the exhaust manifold. I haven't had to deal with any of this on my SS since a;; the **** is gone Anyway...I replaced the left side check valve with a unit from Advanced Auto Part. The part number is CV8 made by BWD Automotive for $16.59. I haven't reset the PCM for the SES light yet; so I don't know if this fixed it. The original valve wasn't completely blocked, I could blow air through it but not as easily as the new one. Advanced only had 1 in stock so I'm having Autozone get me another one from their warehouse for the driver side; it'll be here this evening.

I figure as easy as they are to replace I'm doing them both.

I will be resetting the PCM this evening too, using this procedure:
Turn key on, don't start car
Pull PCM BATT and PCM IGN fuses in engine compartment
Wait 5-10 min
Turn ignition off
Replace fuses

Haven't had to reset my PCM ever, will this work?

 

That'll reset the PCM, but also all the readiness tests and idle will have to relearn. Just for P1416 I wouldn't bother resetting it, after 3 cycles and the air test is run it'll turn off by itself. Won't hurt to drive with it.

 

Ok...installed the other side from Autozone made by Sorensen part # 779-2929 $10.99. Just for the hell of it I reset the PCM and so far so good. I drove it a bit and no SES. I'll keep you all updated if this fixes it. At least the part numbers are posted.