Service Engine Soon LAmp

[or_netboy]

I have a 2002 Yukon with 58,000 miles- on a recent road trip to So. Cal from Oregon, we stayed in So. Cal for about two weeks- about a week into it, the freaking Service Engine Soon lamp came on-
any ideas whay it is...
Can I manually read the codes
I think its probably something indicating emissions- like O2 sensor or damage to the Catalytic Converter--

Please advise- how do I reset this or turn this damn indicator off

[2kflhr]

O2 sensor most likely if you are not experiencing any performance problems. Take it to an Auto-Zone or Parts-America and they should put their code reader on it and identify your problem.

[2kflhr]

Not sure about your model year but on the OBS' you can disconnect the positive battery cable for a minute or two and that should reset it. The code will still be stored.

[rgloston]

My '02 Yukon's service engine light starting coming on about a month ago. Took it to Autozone, and had them check the code. It said something in regards to Catalyst threshold had been exceeded in Bank 2. Could have something to do with excessive fuel deposits (unburned) that got in the Catalytic Converter, burned off as heated, and the O2 sensor behind it triggered when it detected data outside what is theoretically classified as normal operating threshold. After a month, deleted the code twice, the code showed up a third time. I drove my truck for a week, and the light went off on it's own. Freaky, I thought. A week later, it's back. I'll check for myself when I get the Hypertech PPIII that I bought on ebay a week ago.

Just purchased Hypertech's PPIII on ebay last week. When item arrives, I'll test out for myself. I may post an update later.

*Stock Stats*
0-60mph time: 9.2 seconds
Max MPG (city): 312 (gas light came on) (agressive driving)
Max MPG (hwy): 365 (gas light came on) (cruise @ 80mph)

**Note: Upon applying wide open throttle (stock config), there seems to be lack of "high torque feeling" in the low RPM band. Will this improve (at least slightly) with reprogramming.

[Enrique90042]

Check your fuel cap! make sure its on correctly, if you dont have one then thats ur problem!

[tommbo]

yup..check the fuel cap...my 2005 with 700 miles had the check engine come on...bad fuel cap....