Any ideas here? My wife took my 90 xj to get the emissions test. Everything was just fine and passed with flying colors. However when the high speed section came the CO section failed miserably. Yhe stay of utah allows a 1.83 I believe, it was registering 4.61 I think. Yhe guy said it was really strange since everything else was just fine in the idle test. I have no clue what it could be. I've recently replaced the head gasket and with that replaced all vacuum/air lines. The engine is the original inline and there are no other mods on it. I have no idea as to where to begin to diagnose this issue. Could changing an air filter fix the issue? She is my daily driver and have no issues with how the engine runs.

 

Can you scan and post up the actual sheet?

 

High CO is a run rich problem, could be a cracked exhaust mani, loose exhaust/intake, vac leak or O2 sensor.
I would look in these places first.

 

Yep. Make sure the intake manifold bolts aren't loosened up and that the vacuum line from the throttle body to MAP sensor is perfect.

 

As soon as I get home in an hour I'll post a pic of it.

 

I'll definately look into these places. When I changed my head gasket my manifold was craked and I took it to work and re welded it. Hopefully it didn't crack again.

 

 

Here is the result

 

dammit, i hit my head on my desk, turning it to view that