Check engine light on but no code

[armadasx]

I've got no clue what to do. I went thru emissions today. I failed. The guy that ran the test has no clue why other than because the light is on. My check engine light has been on for a while because of both my upstream and downstream O2 sensors were bad. I replaced both sensors and a 15 amp fuse under the hood. My check engine light came back on just after I replaced the O2 sensors so I ran it for codes. The scan tool shows no codes? Why would the light still be on.? Even the print out from emissions shows no codes

Oh,btw its a 4.0 99 jeep Cherokee 5speed

[HitItWithSomeSpeed]

I think its like 50 key starts and/or 50 miles for the light to go off if everything is good to go. if youre not showing codes Id say you just gotta drive it till the computer knows that the problems are fixed.

[Ruepart Hoaxley]

Pretty sure Fred's on the right track. But, that's usually just in the computer and doesn't display on the dash.

I have my scanner, it could be a code from the trans module that a normal OBD scanner can't pick up. You sometimes need a scanner capable of reading the codes from the TCM rather than thwe ones generated by the PCM.

[armadasx]

I should of included that in the first post.ive driven it roughly 70 miles since I last cleared the codes. It's a five speed it wouldn't have a Tcm still would it?

[HitItWithSomeSpeed]

Then drive farther... damn.

[armadasx]

I would but it's unregistered at the moment because I can't get the damn thing to pass emissions. So I can't go to far just 10 to 15 miles at a time on back roads

[HitItWithSomeSpeed]

well, that sucks. if the computer isn't giving codes, and youre passing emissions minus the visual check for the check engine light... pull the bulb and get it tested again?

[hippie metal]

Thats not a 5spd SWAPPED XJ, is it?

[armadasx]

Thats not a 5spd SWAPPED XJ, is it?

Nope,was not a swap

[Daven]

just pull the bulb out.

[armadasx]

When you go thru emissions part of the test is seeing if the light functions.when you first turn the key the light is supposed to come on momentarily and shut off.

[HitItWithSomeSpeed]

welp... youre up shit creek then eh?

[Bigbike]

Burn it to the ground

[customcreationsllc]

You might have a code that isn't engine related, like transmission or body.
Like the other guy said. What kind of scanner where you using?

If you want to cheat it hook the power of the light up to another light that turns on then shuts off like ABS or whatever else is on the dash.

or find a place that doesn't care....

[HitItWithSomeSpeed]

Is your gas cap secured?