98 check engine light...

It came on Tuesday, so I had AutoZone do the check with their gizmo. It said LARGE emmision problem. It just so happend that the dealership I bought the explorer from had it back last friday to do a emmisions test, do you think they may of knocked a hose off or something like that? if so were can I look around under the hood to see if its something simple?

Thanks.

Hello:

I am very interested in your question your check engine light. I own a 1997 Explorer and just recently had the inspection/emissions done. Just a few weeks after I had this done the check engine light began to come on. I had read on some site that this might be caused by a dirty air filter, so I replaced it. That didn't work. My sense is that the mechanid that performed the emissions check knocked sometinh loose.

Please let me know if you learn anything about this.

Thanks,

Bill Dyer

Check that the gas cap is still there if it is not attached to the car. Also check that is it on properly. Most emission tests they check the gas cap, idle/load emissions and sometimes timing. Thats what they do in CA (pre SmogII). Also check for a loose vacuum line to EGR Valve, they may have removed it to attach vacuum pump to test EGR Valve and forgot to put it back on. Only other item is the oxygen sensor(s) 2 or 3 of them.

It was the gas cap, I checked and it wasn't turned all the way.

I disconnected the batt for 5 mins and connected it back up, the check engine light never came back on.

97 Explorer....Get the code read first at some place for free at Autozone and write down the number, not what they tell you. If you get an EVAP leak code like the other guy and it isn't the gas cap, check the vent solenoid above the spare tire. These are known to rust to pieces and stick open.