Thread: Service engine soon light

That must be an older Jeep. On the OBD-II systems that is in your 98 GTP, I dont know of anyway to do such a things. Your best bet is to take it to a place such as Autozone and they will read codes for free and give you the definition of them and then you post that up here and we can see what else we can come up with anything if needed.

My wife has a 1996 Jeep as well and I dont think I can retrieve the codes in the way you mentioned. However, 1996 was the first year for ODB-II and some vehicles that year had ODB-II and some still had the older ODB-I. The ODB-I systems you could retrieve in the way you mentioned or using a shorting clip on the ALDL interface connector.

No, it wouldnt go off on its own like that unless it sees no further trouble. Depending on the code, it can take up to three drive cycles (cold starts, complete warm up and cool back down) before the code will clear on its own if the trouble is no longer detected. Ive never seen an O2 go off on its own like that. Not saying it cant happen but its rare. Typically once they truly go bad, they're done for.

I'm not sure as to why.. but sometimes if the gas cap isn't on tight, the SES light will come on. This can happen with all OBDII cars... mine came on the other day after my first fill up in my new car and went off 5 minutes after pushing it in right and a quick drive around.

Originally Posted by GTFiske

I'm not sure as to why..

Because a gas cap that isn't tight becomes a pressure leak in the EVAP system. The systems diagnoses itself and if it detects a pressure leak it will set a code. Tighten the cap, pressure leak goes away.