96+ Cherokees are not dyno test in Georgia.
OBD2 is always plugged in to a scanner.

 

Here in CA. 96-99 is dynoed while computer is hooked up. 2000 and newer is plugged in to the computer only.

Max

 

Well failed two more tests, just barely. NOx still the problem, now 15mph in the 600's close but no cigar. 25mph is good. Changed thermostat to 180, cooler plugs, new Front O2 sensor, found another exhaust leak at collector before O2, and two cans of seafoam down throat. And new coolant temp sensor. Next step I guess we'll be Map. Did find a pass or don't pay test place.
The old plugs were ashy, and the new ones Are showing lean but not as ashy. In the two last tests the tail pipe O2 is down to zero so my lean condition has gotten better. I guess after the MAP it will be a new cat or some sort of CTS or IAT sensor mod to get a hair richer mix.





3/19/16





After full can of seafoam 1/3 at a time

 

I'm sitting about 180-200 ppm over for passing at 15mph, does anybody think dropping down to the 160 thermostat would get me over the last hump

 

No you should not even have the 180 stat.
Should be the factory 195.

Get one of those $45 dollar performance-curve spun cats. My 94 passed no problem and I had a similar problem as you.
I could pass the 15mph but not the 25mph test.

 

Test #5 fail again, changed IAT and MAP sensors, no change. I guess it's off to get a new cat?! SUCKS, starts up right away, no hesitation, good pick up, in general a very good running truck for her age.




Test 5 no change from #3