SES light on while driving off at idle??

[Trans Am]

95 formula a4,

tonight the SES light came on while driving it stays on while driving, but when i am stopped at traffic lights for longer with the engine idling it goes away and comes back on as soon as i accelerate. The engine doesnt seem to have lost any power.
What do you think might be, i have no way to scan it, and it is a 95 so obd1 with obd2 connector, and no way to flash the codes as in pre 95 cars thanks gm

I have put a new k&n filter about 500 miles ago, do you think it might be the oil from it contaminated the maf?

[Injuneer]

Actually, 1993 was the last year you could flash the codes on the SES light by shorting the ALDL pins. You need to get it scanned. There are used OBD-I scanners available, like the Auto Xray for less than $100. Some came with the 12-pin to 16-pin adapters for the 95's, or if they didn't, Shoebox has a photo of how to jumper the 12-pin OBD-I scanner cable to a 16-pin 95 connector.

Or, you can get free downloads of OBD-I scanning software - TTS DataMaster or FreeScan - and use a cable ($50-100) to connect from a laptop to your PCM.

Without scanning, you are only guessing.

[Trans Am]

i know i m just guessing, i was hoping someone who had the same problem could tell me what was wrong with theirs...light goes of while at idle , on when revving up or driving, off again at idle

It will take a while until i find a scanner, there are some on ebay but the ebay in america, and not over here , and most of them dont want to ship to europe either ..couldnt find a cable usb to obd1 .. But i was thinking, if the light comes on when i rev the engine up, then it must be something with the fuel in the exhaust , maybe the o2 sensors, maybe maf is dirty and too much fuel goes into the chamber, and the o2 sensors pick that up and illuminate the ses light? just a guess, i most probably am wrong, but still what do you think?

[Injuneer]

Possible. Or could also be a sytem that only works when the engine is not idling, like EGR or EVAP. Could be the engine getting an irrational input from a sensor, like a TPS sensor with a dead spot in the winding. May be realted to the transmission shifting. Could be a faulty vehicle speed sensor. Maybe a faulty IC Module that overheats under load. Maybe a loose connection on something that wiggles when the engine flexes under load.