Failed emmisons test :( help!

I got a 92 xj with a 4.0L ho. It has a magnaflow cat and flowmaster muffler. Just did a tune up and replaced the spark plugs, wire, car/rotor and did the sea foam thing. It failed a emissions test today with the following scores:

----------------------Max Allowed------------Vehicle reading-----------------Result

Hydrocarbons (HC)------ 0.9900 ---------------- 1.0433 ---------------------FAIL

Carbon Monoxide (Co)---12.4300 ----------------10.1546 --------------------PASS

Oxides of Nitrogen(N0x)---1.5500 ----------------2.3567 ---------------------FAIL

I was thinking the high flow cat might be the problem? Someone suggested the o2 sensor but it was replaced about a year and a half ago....should be ok?

Any ideas?

it doesn't take long for a poorly tuned engine to take out an o2 sensor. or a catalytic convertor. high NOX is usually related to the egr system. I dont remember if you have EGR or not. (I drive an 86 w/a carbureted 2.8l) hth

Usually HC and CO are diametrically opposed to NOX. i.e. Running rich will reduce NOX but increase HC & CO. Running Lean will be vice-a-versa.

You've got both to high, leads me to believe you have multiple problems.

The EGR's main function is too reduce NOX emissions, I'd test that out and clean it up and the tube leading to the intake, that tube clogs often.

'92XJ? Doesn't that have the ability to read the PCM Fault codes with the key On-Off-On-Off-On method? Try it, find out what codes you have and try to fix those codes, that is likely to solve your problem.

I got a code 33...something to do with the a/c

Anyone a emissions expert here?

Well, you could drain your gas tank down to a couple of gallons, then put in a pint of 100% alcohol from your local drugstore. It will not solve what is causing your engine to fail right now, but will get you past the emissions issue while you fix the problem.

an HO motor doesn't have an EGR system only the older renix motor 87-90 so that is out......