Loss of Power SES light

[thirstyzr1]

Hi all,
Finally got my 90 out of storage. Put on a corsa cat back and started driving. All good 160 miles. Yesterday it started rough part way through the day. Shut it off and restart, ran fine. 20 mins later while passing a farmer pulling bails of hay it felt sluggish. Then noticed the SES light on. Drove like the power key was off. Got home and found a code 43.
Drove it today...warmed up found some farmer to rip by..no issues. Light didnt come back.
Looking for your thoughts...thanks.

[Kevin]

sounds like a vacuum leak

[thirstyzr1]

Thanks...ill start checking lines

[A26B]

DTC 43 is Electronic Spark Control Circuit
Given you were accelerating whent the SES light came on & then was OK later, it's likely the DIS System was in bypass mode while the ECM was running a knock sensor test, causing the code 43 to be set. When the SES light comes on, Full Power Mode is disabled, causing your low power condition.
If it continues to appear, may be the knock sensor going bad.

[G8nightman]

I had the code 43 come on replaced my knock sensor and my chip all good after.

[thirstyzr1]

Thank you gentlemen, i found one hose with a split end. Temp repair for now. Local chev dealership was outta stock.
Will monitor when/if it happens again and go from there. Hope its as simple as a knock sensor/ chip. Maybe time to up grade that chip.

[G8nightman]

If it is the chip and you upgrade the chip with Marc's piggy back chip you will still have a problem the knock sensor board is on the actual factory chip unless you have a 90 then it is separate.

[thirstyzr1]

Its a 90.