94 Sts Help

[Dave Brooks]

Just this winter my check engine light soon started coming occasionally, going off only after the car was shutdown and sat for 10-15 minutes.Replaced plugs - looked ok, replaced fuel filter, air filter, cleaned all electrical contacts I could easily get to and the problem still persists. Mufflers and pipes are good- replaced in the last year. The light comes on within 5 minutes and aprox 5 miles If it comes on at all. That is the only pattern I can detect. It was suggested because the converter is original to the car- 238k+ that the converter may not be warming up quickly enough, and some have suggested that the rings may be just worn enough to allow slight blowby at warm-up to trigger the oxygen sensor. The car starts right up even in very cold weather and runs smoothly. Oil gets changed religiously. Mechanics and dealers are economically out of the question unless something major knocks the car down. The trans was replaced 2 years about ago and the engine seals were replaced as was the throttle position sensor and some other component that I don't remember. Personally replaced the water pump,and the thermostat. The car runs at 203-210* unless it is over 100 outside. Having the ac on or off doesnot affect this problem. The car runs fine with the light on but it just bugs me that I can't get the engine codes off the connector under the dash like Chilton tells you to. There are not enough wires there possibly because of the security system. I drive 70 miles a day, express way and stop and go traffic and get 22 avg mpg. I do not use anything but premium gas. I'd really like to resolve this without a major mechanic visit. I have even considered that possibly an injector might be leaking fuel into the converter at higher rpms. This is the smaller of the two NorthStar engines. Also I am wondering if a weak coil pack could be causing this?...
I love this car and need it to live another 200k plus.
Any help appreciated.
Dave 8^) :feedback

 

[MAC1]

Hopefully, you will find out what the problem is by checking for trouble codes as I suggested. However, I'm a bit skeptical since under the dash connection indicates that you need a code reader.

 

[Dave Brooks]

Thanks Mac

Hopefully, you will find out what the problem is by checking for trouble codes as I suggested. However, I'm a bit skeptical since under the dash connection indicates that you need a code reader.

Mac or anyone,
Is there a commercially avalible code reader?
Dave

 

[Dave Brooks]

Mac,
Thanks for the url on the code reader instructions. It was an intermittant fault on the EGR valve pintle. I removed it, cleaned it and the electrical connection. The light has not come on. Also saw that the molded rubber connectors are starting to dry to dry out and crack. I need the one that goes on top of the air intake with the three nipples. I expect that is a dealer item.
Thanks again for the help! 8^)
Dave