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Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
Well, I did find some evidence that it might be the downstream sensor, if I am understanding my code reader right.
My spanking new Harbor Freight ZR4S OBD2 Code Reader shows for the catalytic converter, the Monitor has not yet run its diagnostic
testing, every time I run it.
Okiedokie, I guess I need to get out on the interstate more. After a good warming up, some idling long idling, etc., I went to the interstate and got stuck in 35 MPH traffic. Then got to run about 70 for a few miles in 4th gear. Not a real Italian Tuneup, more like a Neapolitan Tuneup. Finally turned the little C oval to green.
I find early ODB II cars to show that catalyst monitor test run only after significant driving. But that test is not a DTC and doesn't indicate that anything is broken or out of spec. If you had a DTC of P0420 that would indicate a possible problem.
I find early ODB II cars to show that catalyst monitor test run only after significant driving. But that test is not a DTC and doesn't indicate that anything is broken or out of spec. If you had a DTC of P0420 that would indicate a possible problem.
This is the first time I've seen an indication that the test ran, ever. Have only had scan tools for about a year or so, and this is a new one that shows the user which tests ran, and which did not. For the past couple of weeks, this one always showed red flashing (not run) for the CAT test. A few years ago the CEL burned out, from being tripped by the CAT.
See the rest of this thread for what's going on now.
My similar level code reader has only showed my 95 Subaru cat monitor as run a few times in as many years. All of those were not driving around town, but road trips, or at least hour long highway trips to Phoenix. It has never showed me a P0420 or similar cat related code because there is nothing wrong with that car. Keep in mind that the computers and software in the first few years of OBD II starting in 96 in most markets is like a Fairey Swordfish compared to the F-22s we are driving now. If you have the code reader on there when you start it you can watch a few other of those monitors show not run at first and then they fill in over a couple minutes.
12-15-2021, 09:06 PM
