Ok, I know J-cars pretty well.. but this one's got me f'n confused!!!

Friend's car, a 99 Sunfire w/ 2.2L automatic... check engine light comes on, pull the codes, it's P0420 (Catalyst System Low Efficiency) so, okay the cat's gone. Can't take the car thru emissions tests (called "AirCare" here) with a CEL, it will fail. But, with her car being a 99, they don't do a driving test like the older cars (up to 98 now) have to do, they just plug into the OBD2 port and see that the monitors are running properly. Cash at the moment was an issue so, I figure if we can prevent the code from coming back using an O2 simulator, the CEL will go away, and it should pass Aircare no problem.

So, I install an O2 simulator on the rear sensor... three wires... no problem, CEL goes away, all is fine. A couple of weeks later, she goes thru AirCare... get this, it doesn't fail.. it's "Rejected"!! All the "On Board Diagnostic Tests" were run, pass on them all. It was rejected because of this:

Your Vehicle's On Board Diagnostic System was interrogated
Readiness Monitors: The following monitor(s) were not set:
Catalyst, Evaporative, Oxygen Sensor, Heated Oxygen Sensor
Diagnostic Trouble Codes: No codes identified

So... I'm trying to think WHY this happened. When I installed the O2 sim, I reset the computer. The ONLY thing I can think of, is that she didn't complete enough "drive cycles" to get the monitors running properly.

Anyone have any other ideas? She's going to get a new cat this week... but if I'm right, and the monitors weren't set yet... they won't have time to set before she gets the new cat on and then goes to Aircare again... so she'll just get rejected again...

I hate emissions...

...j

Quote:

I hate emissions...

Me too. Glad that I don't have 'em. Only the Cav would pass, and I think that's even iffy.

John Lenko wrote:The ONLY thing I can think of, is that she didn't complete enough "drive cycles" to get the monitors running properly.

thats exactly it.



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Yeah John. I would say it's that you didn't drive it enough. to let the monitors warm up. It takes a bit obviously. How long did you wait before you tried to get it through emissions?

Miles Prower (Formerly Nari) wrote:How long did you wait before you tried to get it through emissions?

Three weeks. I don't know if she goes 90 km/h enough (that was given as the speed in the "drive cycle" in the service manual)

Gotta do the drive cycle or the obd-II emmissions test won't work and it'll fail.