1994 Stock Automatic with 96K miles and the 'Service Engine Soon' lite usually comes on after driving 15-20 miles. New plugs & wires were installed about 10K miles back. Recent history - I had the oil changed at a different franchise place than usual. A couples days later the engine stalls in a sharp left hand turn, the 'Service Engine Soon' lite comes on, then it comes back to life but the lite stays on. I checked under the hood and saw the tech had not secured the air filter back in the housing correctly and it could 'slide' around. I hoped the problem could be solved by putting the air filter in and securing the housing correctly. The engine performance seems fine but the 'SES' lite still cam on about 15 miles down the road. I did some reading and jumpered #4 & #12 pins on the ALDL connector as shown. On #1 Module I got a C 12 DTC, and on #4 Module I got a H 36 DTC. and three - on all other modules. I removed the negative battery cable for 20 minutes and reinstalled. The test ride performance seemed fine but there that lite is again about 15 miles down the road. I jumpered #4 & #12 pins on the ALDL and got the same results. I removed the 'N' battery cable and replaced it then jumpered #4 & #12 pins on the ALDL to see if the DCTs were clearing. The C 12 is still there but the H 36 is gone. I am waiting for the monster to cool down to check the MAF connections. When the 'SES' lite comes on the digital temp reading is under 200 and the temp meter is close to that but when I stop I can hear one of the electric fans running. They never came on before until teh temp was near 230. Any advice out there?